This episode begins with Tsubomi’s mother showing a tape of her ultrasound to Tsubomi, Rea-pi, Yae, and Saya, with the girls asking her if it’s a boy or girl? Tsubomi’s mother tells them since a penis is not visible then it’s most likely a girl, and Rea-pi gets a kick out of the fact that Tsubomi’s mother used the word penis. One of the girls ask if there is a more complex test but Saya says that the penis is the most prominent diffrence between boys and girls.
The next day at school, Tsubomi is greeted by Daiki and she immediately look at his shorts, and gets embarrassed by the fact that she now relates boys to penises. Later, that day the kids have to sit through a health video about puberty and the differences between boys and girls, and after the video and at swimming class Futoshi starts to ask the other boys to judge the girls breast sizes and if they can tell who’s an adult and who is not.
Later while the girls are changing Yae seems upset about Futoshi’s comments about breast size and she asks Tsubomi if guys really only like large breasts, and then Tsubomi understands that Yae is attracted to Yuu, and later she admitted that she and Yuu are going out. As the girls head back to class they overhear the boys lead by Futoshi rating the girls by points, and as the boys are about to give a cruel rating to Rea-pi Futoshi says you can’t rate her because she’s a pig and not a girl, then she bursts into the room going off on them.
Later at lunch Rea-pi takes almost no food because of the comments the boys made, and she is very hungry. But Saya tells her that Futoshi must like her because her because he actually stoped them from giving her an actual point rating, and Rea-pi gets embarrassed and denies that there might be any attraction between her and Futoshi, Tsubomi thinks that it’s a confusing situation when boys and girls can’t be honest.
After school Tsubomi remember that she forgot something and goes back inside to find it and while she’s in the classroom Daiki walks in and suggests they check the AV room, he thinks that she had it out then. While they are locating the handkerchief they get locked inside the AV room, and the caretaker can’t hear their pounding on the door because the room’s soundproofed.
As they realize that they are on the first floor and can go out the window they see Yae and Yuu kissing outside the school. After Yuu and Yae leave, Daiki jumps out the window and must catch Tsubomi, she lands on top of him and they are both embarrassed because she might have felt his penis and he might have felt her breasts , and he runs off leaving Tsubomi.
That night Daiki has a dream of Yuu and Yae kissing then he dreams of him and Tsubomi kissing and what do you know he wakes up after having a wet dream.
The next day at school Daiki is uneasy around Tsubomi and he stops Futoshi from talking about porno magazines in front of her, and soon Futoshi is stating that Daiki has fallen for Tsubomi. As she is leaving, the little charm he gave her earlier falls of her backpack but he’s unsure about giving it back to her.
Later, Daiki has a talk with Saya about Tsubomi and himself and she tells him it’s natural to think about strange things about a person your interested in and she tells him that Tsubomi is looking for her lost charm. He goes to find her and return it to her, he walks up to her and returns it to her in front of Rea-pi and she’s not satisfied with their explanation of their relationship.
This episode continues with the theme of boys and girls growing up and discovering the differences between the two sexes. Some of the funniest moments come from Tsubomi’s friend Rea-pi, like how she got a kick out of hearing and saying the word penis after Tsubomi’s mother used the word during her ultrasound showing, and when she says that now she understands what they mean on TV shows when they use the word boner after viewing the health video.
This episode also continues with the issue of Tsubomi becoming more aware of the male/female interactions around her. Just a little while earlier she didn’t notice the little glances and gestures that the boys and girls exchanged without even realizing they were doing it.
Now to the boys, didn’t almost all of us males at one time or another act like Futoshi in our youth, rate girls by points, equate breast size to a girl’s value, and knowing no better way to show our attraction to a girl other than acting like a goof or picking on them.
And now about Saya, I’ve read the manga so I’ll keep my comments to the anime only, Saya is vastly more mature about boys and girls than any of the other children, it’s almost as if she’s the puberty/relationship fairy. With only one episode in the OAV series left the anime viewer will more than likely have to read the manga if you want any closure about Saya.