My younger brother is a bully?

Three siblings, deeply in love with each other, suddenly hit puberty hard. It's been three weeks since their younger brother ran away from home and they lost contact. Jeong-gook, who lives in South Chungcheong Province, is extorting money from Yeo-ju in Seoul? Of course, I didn't know it was Yeo-ju. But... my younger brother is a bully? May 12, 2021~