The episode opens with Ami attempting to flirt with Ryuji. Taiga does not have a good reaction to seeing this is not good. Ami plays it coy while Ryuji attempts a sort of awkward “it’s not what it looks like” song and dance. Meanwhile, Minori is calling to Taiga, wanting to know if Ryuji is there. Taiga responds that no one seems to be home, which prompts Ami to ask why Taiga is lying.
Later we see that Ryuji is making dinner. Taiga is sitting at the table, the very picture of “despondent.” Ryuji’s mother walks in, asking why Taiga seems so sad. Taiga does not respond directly. Instead, she makes passive aggressive comments. Ryuji attempts to explain about what the scene with Ami was about, and tries to apologize. Taiga however, completely rejects his apology.
Taiga’s anger continues into the next day and the situation is made worse by both of them being late for school. When they get to class, Ami continues her flirtation campaign, much to the annoyance of Taiga. They exchange insults and things look like they might head toward a full scale fight, but Minori arrives and distracts everyone by being extremely hyper.
We learn that the school’s pool will be opening the next day. Taiga greets this news with an expression of absolute horror. Meanwhile, we learn that the teacher is searching for the perfect romance before she is too old to catch a guy. The teacher becomes incensed when she overhears her female students complaining about how much they weigh and how much they dislike their bodies. (This scene would have been funnier if the teacher had been upset for body-positive reasons instead of jealousy because she feels old and doesn’t have a boyfriend.)
Next is a scene where Ryuji and Minori are dragging Taiga to a store to buy a swimsuit. Taiga is protesting that she does not need or want a swimsuit. She becomes even more annoyed when it turns out that Ami is also at the store to buy a swimsuit. (Apparently, this is the only store in town that sells swimsuits.) Ami decides teasing Taiga about how small she is would be a great idea. (Spoiler: It is not a good idea.)
The swimsuit hijinks continue, with Ryuji blushing and being generally not very helpful in the selection process, and with Ami being a brat. Taiga is having major problems with picking a swimsuit because she is very small, but at the same time refuses to try to see if the child-sized swimsuits fit. Ryuji attempts to help, and gets her to pick out one of the swimsuits.
Taiga however is still unhappy. When Ryuji attempts to discover what she is unhappy about, she states that she does not know how to swim. Ryuji doubts that this is the real reason however. We eventually do discover the real reason, and it turns out that Taiga is extremely self-conscious about a certain lack of “development.” She is especially self-conscious this time around because she does not want Kitamura to see how flat she is.
This results in sewing hijinks, where Ryuji creates some padding for poor Taiga.
At the pool opening, Taiga is still extremely self-conscious while Ami is the exact opposite. (Ami is of course, pretending to be sweet and modest while actually being extremely vain.) There is another encounter between Taiga and Ami about Taiga’s development. Taiga however is able to win the argument thanks to Ryuji’s pads. (She also manages to impress the boys at the pool.) Minori however is not fooled!
Kitamura heads over to Taiga. (He is able to recognize her from her figure but not much else since he is without his glasses. It is interesting that he mentions recognizing her by her figure, even though Taiga’s figure has changed due to the pads.) Taiga becomes extremely bashful, and yells at him to go away. There are some more pool hijinks with people throwing each other into the pool. Ami decides to dump Taiga in the pool, unfortunately, it turns out that Taiga really cannot swim, and Ryuji has to rescue her. In the process, Taiga loses her padding. (So, he also has to rescue her padding.)
Later, we see Ami, Ryuji and Taiga in the classroom together. Taiga is furious and miserable and does not accept Ami’s half-hearted apology. Ami decides to invite Ryuji to her beach house. (So she can point out that Taiga cannot come since she cannot swim.) Ryuji is a little baffled about the change of subject, since Ami was supposed to be apologizing to Taiga. Ami states that other people can come to her house for vacation. Taiga attempts to use her blackmail material, but Ami says she will sue Taiga for “infringing on portrait rights.”
The argument is interrupted by Minori, who would like them to stop fighting. Taiga and Ami immediately begin tattling on each other to her. Minori repeats her stance on not fighting and tells them if they want to “fight”, they should do it through competing at sports.