Kou Tanaka (田中 洸 Tanaka Kō) is the male protagonist of the Ao Haru Ride series. He is a 2nd year High School student whose first love is Futaba Yoshioka.

Personality: When Kou was younger he was very outgoing and kind, which made Futaba fall in love with him. After his mother's death and other issues he ran into, Kou changed, which was hard for Futaba to accept (it even took her a little while to call him by his new last name Mabuchi, because he wasn't Tanaka anymore). He is now more masculine, sarcastic, and rude. He can come off very harsh, even when he doesn't mean to, which sort of makes him hard to talk to (Aya sometimes helps Kou with clearing up quick misunderstandings of Kou personality with his own very happy and bubbly atmosphere). In addition, he has extremely pessimistic views about himself and about his brother. Despite these changes, it is evident that Kou is still an overall kind person.

At first, Futaba didn't like Kou's new personality, she found him very harsh and hard to understand but later falls in love with not "Tanaka Kou", but "Mabuchi Kou". Kou lightens up more around his new found friends such as Futaba, Aya, Yuri, and Shuko.

It is shown that after coming to terms with his true feelings for Yoshioka, he becomes a more happier, open person and starts to resemble his old self in middle school.