AKB48 Sousenkyo Senbatsu Prediction – Why Satou Amina is the real Cinderella Girl

Branching from my love of anime, I have been very into various idol groups over the last few years. I started off with Morning Musume, fell in love with Idoling!!! (still my favourite group) but has recently warmed up tremendously to AKB48. It’s very easy to find subtitled materials online so that has helped my consumption level and my ability to get to know many of the girls. My oshimen (favourite member) is Sato Amina because I am a sucker for an underdog and she personifies that more than anyone in the AKB48 family. It is well-known amongst fans the level to which she got shafted after the first Senbatsu Sousenkyo when she placed 8th (for a more complete article of what makes Amina special, please read this blog by aakun. I started really paying attention to her because of it). I want to go one step further and try to see whether she there is any other girl who ranked better in the election despite getting no, or minimal, push whatsoever.


With the exception of Election singles (when fans elect who enter the senbatsu) and Janken singles (when senbatsu places are determined by a tournament of rock-paper-scissors), AKB48 management chooses who are representing the group for each singles. This allows them some power to give exposure to those who are popular or those who they want to groom to be the next popular members of AKB48. I am planning to use this as my proxy to measure how much each members get pushed and compare that against their election results, to see who well being pushed translate to increased or continued popularity among fans.

I decide to use the regression analysis, with senbatsu appearances as the X variables (independent) and sousenkyo ranking as the Y variable (dependent). In effect, I want to try to predict the sousenkyo ranking based on the senbatsu appearances. The difference between these predicted numbers and the actual results should give an indication of which members should not be as popular as their senbatsu fate suggests.

Here are the results. The Diff column represents [ACTUAL SOUSENKYO RANKING – PREDICTED RANKING]. Thus, the more negative the number, the more popular the associated girl is than she has the right to be given her senbatsu exposure. Conversely, the more positive the number, the more the push does not work as well as it should to make the girl popular.

Table Member 2

Note that:

  • Predicted ranking = Average ranking a member should have gotten based on their cumulative senbatsu selections
  • Actual ranking = Average ranking over the past 5 sousenkyo results, as voted by fans
  • Names highlighted in red are those who have not appeared in any senbatsu and the regression predicts them a ranking of 43.5 (see methodology for more detail)
  • Names in white (10-43) are within one standard deviation of the mean, representing around 68% of all possible value. Name in lighter orange and blue are within 2 standard deviations, representing around 95% of the values. Names in brighter colour (1-2 & 51-54) are outside 2 standard deviations (See Wikipedia for more explanation). Thus, those are the ones who are not likely to get the results by chance.

Comments on the results:

  • Amina is undoubtedly the Cinderella girl as far as not getting pushed and still getting amazing ranking. Her score is way ahead of Glad to see my analysis proving this quite emphatically. Her score is way below anyone and is actually outside the 3 x standard deviation range, meaning that she is statistically outside the 99.9% of all possible results – a true outlier indeed. I would attribute the discrepency to how awesome she is as an AKB48 member despite all the ignorance by the management. It makes me feel how incredible it is that she manages to cultivate such level of support despite getting zero senbatsu push whatsoever
  • I’m also not too surprised to see Umeda, Kuramochi and Masuda ranking 2-3-4 respectively. From my impression of what I have read online, they are the members who have not exactly been pushed so hard yet still maintain a sizable fanbase that propelled them up the ranking once the sousenkyos came.
  • On the same topic of getting no push, out of the 4th generation that are still around, three (Amina, Oya and Nakata) have had no single senbatsu appearance whatsoever. The remaining two (Kuramochi and Fujie) had three each. Talk about a neglected generation…
  • On the topic of generational comparison, I summed up the predicted ranking and actual ranking for each generation and this is what I got. Given their senbatsu appearance, 4th gen prediction is among the lowest, barely on par with 7th gen. On the other hand, 10th and 11th gens are pushed pretty hard, yet without the results we can yet see.
  • Gen Rank
  • I read a post recently that said that 7-8-9 gen are forgotten-extinct-manager’s favourite in that order. The predicted ranking does show that as 9th gen should outrank 7th by 5.4 position (36.6 vs. 42.0) and 8th gen is nowhere to be seen
  • On the other end of the scale, Kawaei and Anna are the push that has not yet panned out. Suzuran and Lemon also rank quite high in that regards.
  • 6th Gen is only one person (Akicha) so it is difficult to read too much into the result.
  • When it comes to early generation pushes that have not been as popular as expected, Mii-chan and Myou come to mind, ranking 43rd and 45th respectively.
  • The majority of the 1st gens, such as Kojima, Acchan and Takamina had received similar ranking to what their push should give them.

Last Words

Amina’s time for more exposure has definitely passed. I wonder if she got the push she should have, how popular she might actually be. She will still remain my favourite member regardless. It is interesting to do this analysis to try to confirm the anecdotes that have floated around the fandom. Push works, but there are always those, such as Amina, who refreshingly forges her own popularity through their own means, if only for a short while.


  1. I collected the senbatsu data and members’ data, courtesy of stage.net website
  2. For each member, I figured out how many singles she is active, namely when she first became a member or a kenkyuusei (i.e. 4th gen is not announced as part of AKB48 until after BINGO! So those earlier singles do not count)
  3. Find out the percentage of appearances each member made it in the senbatsu over total possible appearances. I.e. Watanabe Mayu could have appeared in 24 singles out of a maximum of 26 (because she’s 3rd gen, she was not in AKB48 during the earlier singles). However, she appeared in senbatsu for 21 singles (missing out on Seifuku and Keibetsu, the two early singles). Therefore, her senbatsu score would have been 21/23 or 91%
  4. For the X-variables, I eventually used center selection, frontline selection (i.e. media senbatsu) and general senbatsu position.
  5. I ran a 3-variable regression in excel.
  6. Using the regression, I then worked out the predicted ranking.

The regression cofficients that I ended up with are:

Predict ranking = 43.5 – 38.4 (Senbatsu Count) – 37.8 (Front Position Count) – 44.3 (Center Position Count)

  • From this, if you appear in no senbatsu at all, like in the case of Amina, you will be predicted a ranking of 43.5.
  • Any appearances in the senbatsu, or better, will lower the predicted ranking accordingly.
  • The R-squared that I got from this particular regression is 76.9%, which is pretty good


  • I am only doing this for the AKB48 members. I excluded all members that never made it into the sousenkyo senbatsu ranking.
  • For the senbatsu count, I excluded sousenkyo and janken singles since those are not determined by the management (at least that’s what I will believe)
  • For those who went unranked, I assigned the following scores for each sousenkyo to represent such status numerically: 1st = 40, 2nd = 50, 3rd = 50, 4th = 70, 5th = 70

8 Comments on “AKB48 Sousenkyo Senbatsu Prediction – Why Satou Amina is the real Cinderella Girl”

  1. arifer says:

    Wow, what a detailed research you’ve done for Amina here 😀
    Just one thing to note though, there’s no more 8th gen, so that would explain the 0 for your second table.

    • Thanks for the comment! Glad you like it.

      I guess I just added the 8th gen line there for completeness sake. It still is also quite amazing to me that out of 15 members in the 8th gen, none made it out of KKS. How is that even possible?

  2. Taka says:

    I don’t mean to be picky but why aren’t you counting Iiwake Maybe as a senbatsu appearance for Amina?

    The only thing really missing from this is an explanation of why senbatsu specifically are so important and if it is more important than say variety show appearances. My primary methods of consumption of AKB48 media is AKBINGO! and other variety performances. I generally have little to no interest in the singles or music videos. So I can’t speak for how much senbatsu affects popularity. I do know that Amina is generally a regular on AKBINGO and is pretty quick to speak up, especially in the Danso episodes… I never got the impression that she wasn’t popular. I know purchasing the singles is what allows fans to vote for their favorite member and the like but I wonder just how much it actually impacts the popularity of any given girl. I always viewed AKB as a similar to a cult of personality. In that view I think you wouldn’t be able to get enough of an impression of the girl from just singles. I would feel like Television appearances would be more important.

    Anyway I was vaguely aware that Lemon-chan’s push was backfiring after she was present in so many episodes of AKBINGO!. I generally just think she was too gimmicky. I like her though.
    My favorite girls would be ones like Mariko or Akimoto who are kind of goofballs on AKBINGO. Takamina is funny for her failures as well.

    Last I have to ask if you have watched AKB0048? I thought it was great and it succeeded in making me a fan of AKB48 (albeit not a die-hard one) when previously they were merely something I was aware of but had no real knowledge of.

    • My fault for not really explaining too well (will edit above to make it clearer). I ignore Iiwake Maybe and all other sousenkyo singles because they are fan-based senbatsu selection, hence they don’t capture the management discretion which I am trying to measure. Also, since Iiwake Maybe is directly influenced by the election results, adding that as an additional independent variable to predict election results will create biased result. Since I am trying to find out how management discretion can explain election results, i cannot include variables that are not controlled by the management (or at least that’s what I want to believe!)

      I still senbatsu singles selection as the clearest indication of management discretion. I am also merely using it as a proxy for such variable and it seems to explain the actual results pretty well. I understand that this might also be confirmation bias, but that’s another story:)

      Despite this, I totally agree though that television appearances and also important parts they use to appeal to the public. I would love to try to use that as my additional variable and rerun an entire regression. I just do not have any quick and easy way of going through and capture all the information of those members who have appeared on each episodes. I don’t have all the episodes and do not have time to watch all of them to If such website exists, please share with me!

      For, Lemon, is it the issue of one-trick pony getting annoying over time? On AKBINGO now, it seems like they are trying to push the newer generations. About time since the older generations (including both Mariko and Akimoto that you mentioned) are slowly leaving!

      AKB0048 is in the list of things I want to watch (helps that Amina is also in it!), I am still pleasantly surprised that it does not suck:)

  3. Taka says:

    Sorry I was under the impression that Iiwake Maybe was a regular single. Stage48 wiki doesn’t say anything about the election on the Iiwake Maybe page but it does on the Heavy Rotation page so I assumed that it wasn’t. Wikipedia has it correct in the discography though.

    And yes Lemon herself even says that she wasn’t sure if it was working out in one episode of AKBINGO! The whole Fresh Lemon ni Naritai Yo! and eating raw lemons I think was a little much. Add onto that she is a little strange (she headbutts Amina for some reason in one of the episodes)

    She generally answers questions in strange ways and; while cute, her voice and mannerisms turn off as many fans as they make. I for one like her because she is freaking adorable.

    The reason it doesn’t absolutely suck is because it has a pretty awesome writer/director combo. Shoji Kawamori is already well known for the Macross franchise and Mari Okada has been a bit of rising star in the screenwriting side of things lately (though the quality varies). The first time they got together they made Aquarion Evol my 2nd favorite anime of 2012 (which I just realized is shockingly enough not in the top for 2012 according to your post).

    • No problem:) I’d like to think that Iiwake Maybe is that bittersweet single for Amina fan. It’s probably her favourite song (she said that in one of the profile books a few years back) but she barely appeared in the PV at all, despite coming 8th in the 1st election!

      That headbutt scene is just so cute! It’s always amazing how in Japan, lots of idols, comedians can get by on one trick, just like what Lemon is. I am thinking of Hard Gay with his move or Murashige Anna (and her ‘Mentaiko!’). I guess it is nice to have different personalities in the group, not just the cute, ‘boring’ types. At least she ranked 57th in the last election, unlike many of her generational peers, so the move is somewhat paying off for her.

      Aquarion Evol is actually 16th on that list (just missing out on being mentioned in my post…). It ranked very averagedly across the board. What’s your favourite that year again?

      • Taka says:

        I had a debate about whether to put down my favorite or not. My favorite would be Jojo’s Bizarre Adventure but it’s debatable whether that counts as 2012 or 2013. My favorite parts are in 2013…

        Aquarion Evol is awesome the main problem I think was that a lot of people didn’t watch it because they figured it they would have to watch Sousei no Aquarion which aired in 2005. 8 years between sequels is kind of unheard of (though it’s not much a sequel more of a reboot really). It’s also pretty weird and yeah you do need some? knowledge of Aquarion. I’ve never seen Aquarion but even with out that I loved the ever loving piss out of this show.

        My favorite shows tend to be the madcap insane ones because I just find them so darn creative. Gintama, Milky Holmes, AKB0048, Aquarion Evol, Jojo are some of my favorites that aired recently. I actually moved the latter 2 onto my top 5 list after they aired. For the record Gintama>>>Nodame Cantabile>Baccano=Jojo=Aquarion. I can’t see the top 2 moving anytime soon and I definitely can’t see Gintama ever being toppled unless some other series comes out that is consistently brilliant for 200+ episodes.

      • I have never seen Jojo anime but it is one of my all-time favourite manga series that I read as a kid. I love the 3rd to 5th season when they started introducing stands. I have cooled down on the recent seasons but should really give it a try again soon. For my analysis, I always count series like Jojo as 2013 series so hopefully when I get around to compiling the list for that year, it will be somewhere high up!

        After a conversation with you, I’ve finally decided to start watching AKB0048. Fnished the first season in a couple of days. Very addictive and frankly a lot better than I expected! Nice animation (some 3D works felt a bit out of place though), surprisingly good character and plot and they work in AKB48 music really well. Can’t wait to go marathon through the second season now! At some point, I’ll definitely give Aquarion EVOL a try too:)

        Gintama just seems so long I am a little scared getting stuck into it. So many things on a list of things-to-watch!

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