しっかり！長男

Wakasugi Choichiro, the sheltered eldest son of the wealthy Wakasugi zaibatsu, has been raised as the family heir but lacks confidence, often crumbling under pressure. When his crush Yuki calls him spineless, Choichiro resolves to become a stronger man, leaving home to prove himself. In Tokyo, he meets Koto, a girl who looks like Yuki, and stays with her family, finding new purpose and unexpected feelings, weaving a heartfelt tale of growth, determination, and young love amidst the challenges of stepping out into the world. (Unreviewed summary by Grok 2)