Heart Mark Motto Oome / Many, many little hearts

The main character, Reika, is Yu's older sister and an aspiring manga artist. She works hard on her drawings, and her younger brother supports her in everyday life. However, due to her constant immersion in her work, her behavior begins to change, and Yu finds himself drawn into complex and tense relationships with his sister.

Asai, a girl Yu has feelings for, learns about Reika's activities and unexpectedly becomes her assistant. Over time, the relationships between all three characters become more complicated: jealousy, misunderstandings, and emotional tension arise. Yu finds himself at the center of this tangled situation, not knowing how to act correctly.