Shimamura's childhood friend. Tarumi comes across Shimamura again at Nagafuji's meat store after high school classes. To Shimamura, Tarumi looked more like a delinquent than she did, even though that's not reflected in her personality. Tarumi attempts to reconnect with Shimamura after all these years, asking her to hang out constantly, expecting the Shima-chan of her past.
In the anime, Tarumi is voiced by Ai Kayano, who has work in other yuri anime like Bloom Into You (Yagate Kimi ni Naru) as the character Sayaka.
(Source: Adachi to Shimamura Wiki)