multi-plot, multi-characters, multi-arcs, sometimes become
problematic and stale
Canno's Kiss and White Lily for My Dearest Girl, Takashi Ikeda's Sasameki Koto, for me these works pulled off multiple plots and subplots and characters deliciously. Maybe it's not just the mangaka themselves. Most literary works that are published and much-regarded have passionate editors, proofreaders, etc. Like a well-oiled A-team.