Ninja to Gokudō (Ninja vs. Yakuza) is an action-comedy manga by Shinsuke Kondō in which Shinoha, a stoic young ninja haunted by past trauma and unable to laugh, becomes entangled with Kiwami, a seemingly ordinary corporate employee who secretly commands a powerful yakuza organization. Despite their starkly different identities, the centuries-old conflict between ninjas and the yakuza brings them both into direct confrontation—and eventually an uneasy alliance—as hidden truths and personal vendettas push them toward redefining loyalty, power, and purpose.