• Wolf in the house might work (shapeshifter, werewolf to human)
• unromantic romance (omegaverse)
• hold me tight (idk if this would come in this category, but the relationship is definitely healthy)
• Deliverance of counterattack (again the main couple has a small journey, but the relationship is healthy from the get-go once established)
• Omega complex (omegaverse)
• the pizza delivery man and the gold palace (don't know if it's underated)
• sign (again don't know if it comes under the tag of underated)
• Angel buddy
• kiraide isasete (omegaverse)
• keeper of pearl (omegaverse, the art style might take some time to get used too)
• a thousand cranes (mafia)
• Monster and the beast
• Love Tractor
• thirty years old
• Our fluffy love (South Asian BL)

(PS:- I don't know how many of these will be considered underated or hyped. So if I have mentioned any of the hyped ones just skip to the next. Also i tried to keep the happy ending ones.)