Innocent: Usotsuki Onna no Shiikubako

Ritsuka is a lesbian pianist, and Haru is a girl who lives next door. Haru's mother, Yukiji, has disappeared, and Ritsuka has been taking care of Haru more and more. Haru is in love with Ritsuka, and she flusters Ritsuka with her honest expressions of affection, even though she is very young. Eventually, the relationship between Ritsuka and Yukiji and Yukiji's whereabouts are revealed...... What will Haru do when she discovers the truth?

(Source: wwwave comics, translated)