Obanai's Slimy Vibrator

Obanai is a very harsh and strict individual who shows no concern for those who do not abide by the rules of the Demon Slayer Corps. His expectations for his fellow Demon Slayers are quite unrealistic, as he was seen berating Tengen Uzui for suffering heavy wounds against the "weakest" Upper Rank and telling him to "fight to the death" when Tengen insists on retiring. Tengen's retirement also highlights Obanai's devotion to the future of the Demon Slayer Corps, often at others' expense, such as when he ties up lower-ranked Demon Slayers and uses them as obstacles during Hashira Training for relatively petty reasons. He also sees the newer Demon Slayer recruits as weak and incapable of improvement, expressing surprise when Tengen informs him that Tanjiro Kamado survived the battle with Daki and Gyutaro. Obanai has a rather prominent habit of pointing at people with his finger in an accusatory manner while berating them or talking badly about someone.

Despite his merciless personality, there are two people he cares deeply about: Kagaya Ubuyashiki and Mitsuri Kanroji. He has a crush on Mitsuri, as he often lets his feelings shine through by sharing meals with her and giving gifts, such as the signature green socks she wears with her uniform. Obanai seems to let his overprotectiveness of Mitsuri show at times, such as when he threatens Tanjiro for growing too close to her.[7] It was implied that he has a crush on Mitsuri because of her cheerful personality that didn't let any of the hellish training she had gone through to radiate in the slightest. Talking with her also made him forget all the strife and conflict he had encountered during his past and made him feel as if he was an ordinary young man.[8] Like all the Hashira, Obanai has a great deal of respect for Kagaya too.