Crimson Spell
This is an old favorite of mine
Sex Therapist
Broooo I read this years ago and just now found it again holy shit lol
Absolute Boyfriend
This is an old favorite of mine from back in the day, it's about a 15 year old girl named Riiko who accidentally buys a love android aka the perfect lover (whom she names Knight) for over 1 million dollars lol, they spend lots and lots of time together and ya she falls for his and all that, She has a childhood friend named Soushi whose in love with her but she has no idea so she dates the Android instead anyway its fuckin sad cause Knights internal battery dies and he can't be repaired because he's the prototype so Riika gets depressed and eventually goes to be with Soushi at the end and she has the promise rings
Razoku no Hanayome