I think the uke was a NEET and a swimming instructor at a local pool (or was the seme the swimming instructor? i don't remember). One was teaching the other to swim. Could have been a short story, I'm not sure. NEET uke had light, long hair.
I read it ages ago, it's at least 7 or 8 years old, probably more. My memories are super vague. I think one of them might have had a younger brother to take to the pool but not sure.
Kirato is one very emotionally mature guy. Yuuji is lucky to have someone so persistent, observant and empathetic by his side! The thing he said about "his stomach being too small" about Yuuji's emotions and fear of happiness made so much sense. It's like when a starving person has to slowly start eating more and more because their body won't be able to handle large meals immediately after starvation