It's been ages since I last read it, but from what I can remember:

• uke is a mangaka, very shy, and a shut-in who never/very rarely left his house;
• seme is introduced to uke by one of the uke's friends (?) and falls in love with him;
• the mood was fairly calm/romantic;
• I'm not 100% sure if it was yaoi or just BL;
• the art style was fairly cute/adorable-ish.

If anyone can help, I'd be very grateful! I've been trying to track this one down for years.

Quite some with the same premise but I remember
Vanilla resort
Kimi ga Inakeriya Iki mo Dekinai
Uchi no Tenshi ga Kemono Deshita

Quote from z_goes_undercover

Quite some with the same premise but I remember
Vanilla resort
Kimi ga Inakeriya Iki mo Dekinai
Uchi no Tenshi ga Kemono Deshita

Unfortunately it's none of those, but I really enjoyed them, thank you!
I wish I could remember more details, but it's been so long...

Bump! Still haven't found the manga, sadly.