- The male protagonist of the series. He is a 13 year old first year middle school student. He's a normal guy who's in an age where he starts to be interested in girls but gets mad as soon people call him a kid because of his size. He thinks that he's more of an adult than Natsuki but easily gets embarrassed when she's around him. This could be from his father as he always acted childish and blew all of his money (and company money) at strip clubs. He doesn't really get the difference between swimwear and underwear. When Natsuki's clothes are torn off, she covers herself in embarrassment but he says there's no difference. He never seemed to have an attraction towards Natsuki till after her sister Chiaki asked him if he did, where now starts to question why he has all of a sudden had an attraction towards her when he personally sees her as a nuisance, but most of the time his thoughts leads to some perverted action she has done around him. However, as of recently has started to show feelings for Kanade after she confessed her feelings to him as well as the rumor that she kissed him. However, he finally realises that he likes Natsuki. He confesses to Natsuki in the 26th chapter. In the 'sequel' to chapter 26, Kouta returns to town after four years have passed and reunites with Natsuki in similar way they first met. He is similar to Junpei Manaka(main character in "Ichigo 100%").
Kouta is a nomal, average middle school student. He gets angry when people call him a kid because of his size. Kouta thinks that he is more of an adult than Natsuki but easily gets embarrassed when she's around him. This behavior could be from his father, acting childish and blowing all his money (coporate money) at strip clubs. Kouta has been called a dirty boy by both Natsuki and Chia. He doesn't understand the difference between swimsuits and underwear. Kouta