You've built a year of domestic comfort with these two, so when Nao realizes she's already missed his birthday, it lands different than it should. The OVA doesn't try to manufacture conflict, it just lets that quiet panic sit there while she figures out what she actually cares about. A single episode that trusts you remember the manga, trusts the relationship already exists, and asks only that you recognize what it costs to take someone for granted.
A year into living together, Nao and Uehara have transformed from accidental roommates into an actual couple. As his sixteenth birthday approaches, Nao obsesses over finding the perfect gift, convinced this milestone deserves something special. She's wrapped up in the details, imagining how the day will go, when reality crashes down: his birthday already happened. While she was busy modeling for Asai, a charming hair stylist, the one day she'd been planning for slipped right past her. Now Nao faces the awkward fallout of missing something she didn't realize had already arrived. The mix of domestic comedy and genuine romantic tension runs through their shared apartment, where small moments carry real weight. Uehara's quiet disappointment and Nao's panic spiral create the kind of everyday drama that matters when you actually care about someone. This OVA captures the peculiar vulnerability of loving someone well enough to know exactly how badly you've messed up, and what happens when you try to fix it.