Joker and Kasumi from Persona 5 Royal. I lover her entire story arc and how she plays of Joker. They just look good together and frankly she's the only romanceable character I really like seeing paired with the MC.
Kanji and Naoto from Persona 4. I just think it's cute dammit.
Sora and Kairi. It took way to long for Kairi to get any sort of respect but I just love her entire relationship with Sora over the course of the series and their fight together in Remind is beautiful.
Nero and Kyrie from Devil May Cry. Kylie is sadly underdeveloped but there's something I just enjoy about how unapologetically wholesome this relationship in such a chaotic series, especially if you go into side material.