Time-travel mishap results in a middleschooler remaining single for his entire life. One of his descendants travels back in time to help the boy find a way to connect with the school idol, the one he was meant to marry originally.
Cute story, good humour, although TBH descendant-san seemed like the most interesting character of all.
SUMMARY: Nagahisha is content living a quiet nondescript life of anyonimity until a man claiming to be from the future emerges from his rice cooker. The man announces that because of a time traveler's mistake, Nagahisha's future marriage to the school idol is in jeopardy, and he must fix it before the future is changed.