Arisa Ishino (石野ありさ, Ishino Arisa) is a classmate of Hikari Tsutsui and Iroha Igarashi who was initially annoyed and disgusted on Tsutsui's otaku lifestyle, but she became friends with the two and joined the gang later on.
Arisa has chest-length light-peach hair that is tied in a ponytail with bangs swept to the left (her hair reaches to her hips when she styles it down) where it is sometimes swept to the right side and dark peach-brown eyes.
In Season 2 Episode 12, she cuts her hair to chin-length.
Arisa was one of the first friends to Hikari Tsutsui.
At first, Arisa met Mitsuya after he was apologizing for all his misdeeds against Hikari Tsutsui and instantly finds him attractive. She openly shows her attraction to him much to his dismay, but after spending time with each other, Mitsuya begins to care for Arisa even if he doesn't show it.
In Season 2 Episode 12, she eventually becomes his wife (which now makes her Arisa Takanashi) and she gives birth to a baby boy.
- The name Arisa is written in katakana (ありさ), which has no special meaning.
- Arisa's surname Ishino means "stone" (石) (ishi) and "field, wilderness" (野) (no).
- Her married name Takanashi means "tall, high" (高) (taka) and "pear" (梨) (nashi).
- Arisa is Iroha Igarashi's first female friend.