Kanzo Hattori is pint-sized, serious, and perpetually wearing a blue ninja hood. He is not conventionally “handsome” like Kaneda. He is not a bumbling fool like Kenichi. He is competent, wise, and deeply kind. And Yumiko notices.
The most compelling evidence of a “romantic” undertone is Yumiko’s reaction to Hattori’s female ninja counterpart: . A running gag involves Tsubame, the kunoichi (female ninja) from the Iga faction, having a massive crush on Hattori. When Tsubame visits and acts unusually affectionate (offering to cook for him or hold his hand), Yumiko’s reaction is immediate and visceral: jealousy. Ninja Hattori Sex Yumiko