Dramas like
Our Beloved Summer

The same story told from the other end. Both frame the past through somebody looking back at it, a documentary crew here and a daughter reading her mother's diary there, with the same precision about the difference between what happened and what you remember happening, same conviction that being nineteen with someone marks you permanently. Difference: it does not let them work it out. Our Beloved Summer says we were young and bad at this; 2521 says the times were against us, and it means it.

Hooks early Episode 2, once the two of them start meeting at night. Episode 1 is loud and abrasive on purpose, and it is the easiest place to quit.

For the adults-negotiating-a-relationship-out-loud pleasure. Two people who talk about terms, boundaries and money instead of manufacturing misunderstandings, in a script as interested in rent and career as in romance. If what you loved was that nobody in Our Beloved Summer behaves stupidly to extend an episode, this is the other show that refuses to. Difference: the premise is a contract marriage, so the structure is a negotiation rather than a reunion.

Hooks early Episode 2, once the housemate arrangement starts.

Almost nothing happens and the dialogue is the entire point. A retired sprinter and a film translator saying exactly what they mean, four leads who are all genuinely decent, no toxic conflict and no third-act separation manufactured for tension. Same comfort of watching mature people be careful with each other. Difference: no shared past and no wound to reopen, so it accumulates rather than resolving.

Slow start Episode 3, once all four leads stop explaining themselves and start talking.

The natural companion piece. A woman quits everything and moves to a small town to do nothing on purpose, and the show treats that as a plan rather than a breakdown. Same unhurried, sunlit texture, though the stakes sharpen later than the surface suggests. Difference: barely a romance. If the leads and their chemistry were the draw, this has much less of it.

Slow start Episode 3, once the village regulars start turning up at the library.

The heavier cousin. Same faith in silence, long takes and people who cannot articulate what is wrong with their lives, written with better dialogue than almost anything else on this list. Difference: considerably bleaker and slower still. Where Our Beloved Summer is a warm blanket, this one is airless for three episodes on purpose.

Slow start Episode 3, once Mr Gu starts drinking with Mi-jeong. Before that it is deliberately airless.

Grown-up romance with no villain and no device. Two people already in the wrong situations, deciding slowly and carefully what they are willing to blow up, with the same quiet camera and the same refusal of makjang. Difference: it is about leaving a relationship rather than returning to one, and it has none of the nostalgia or the comedy.

Slow start Episode 4, once both families are involved. Before that it is glances and pharmacy small talk.