Not much is known about Ootani's past but during episodes 24 and 25, he plays the role of a bully. The only person who falls prey to this is Harima, who happens to be the new crew member. Ootani's bullying worsens when he finds out Harima has been drawing manga, and he even tries pierce his hand as punishment. Later, Ootani's attitude towards Harima completely changes when he is saved from drowning. He becomes emotional and even blushes as he says goodbye to Harima. After these events, Ootani is never seen or mentioned again in the series.
Ootani is crude and even cruel at times. He is antagonistic toward Harima very early on and even tries to permanently disfigure his hand simply because he thought the sea was no place for manga. His attitude completely changes, however, when Harima saves him. Ootani becomes emotional and even affectionate toward him, showing a fickleness to him. Aside from this, he seems to be the leader of his group of friends, showing that he has leadership qualities.
Ootani is a tall, lanky man with a bald hairstyle. He has small eyes, angled eyebrows, and a tongue that can be maneuvered like a snake's, which are all characteristics of a villain.
Ootani and Harima start off as enemies, with Ootani being the one to initiate the fight. This is mainly due to Harima being new on the ship and drawing manga. They put aside their differences when a storm hits and Harima saves him from drowning. After this, Ootani has a newfound respect for Harima and even comes to affectionally call him the "Manga Kid."
- Ootani is unable to swim despite being a sailor.