Each episode drops you into a moment where someone's life ends before it should, and the Time Patrol's job is to quietly save them without changing anything that matters. Bon stays conscious when everyone else forgets, which means he alone remembers every life they've touched, every small rescue nobody knows happened. The show treats history like a living thing full of people whose stories deserve finishing, and it never pretends that fixing one person's tragedy is simple or clean.

Bon Namihira is an ordinary junior high student until he crosses paths with Ream Stream, a girl from the future who serves in the Time Patrol, and an odd creature called Buyoyon. The Patrol rescues people who died unlucky deaths that would not meaningfully change history, and anyone who sees its agents has their memory wiped. Bon's memory somehow stays intact, so he is taken on as an agent in training. Teaming up with Ream, he is thrilled by future gadgets like the time boat, which travels through time and space. Missions carry them to many eras and places around the globe. Bon sometimes gets carried away, but along the way he touches the lives of people who lived wisely in their own times.