They could have been happy together but miho felt betrayed and started acting out wanted to hurt uke like how he is feeling. Uke is someone who fear loneliness and easily get attached to someone that shown him kindness and attention. And because of that, miho constantly felt uneasy about their relationship and hence, in order to protect himself, he tried to distance himself from uke and went back to his old lifestyle. This hurt the relationship even more and things starts to went down spiral. After a long painful period, uke finally had enough and decided to end it after realising he had fallen in love with someone else. To be fair, Miho is also suffering but was unable to let go of uke. As a result, they let on this toxic relationship longer than it should.
They could have been happy together but miho felt betrayed and started acting out wanted to hurt uke like how he is feeling. Uke is someone who fear loneliness and easily get attached to someone that shown him kindness and attention. And because of that, miho constantly felt uneasy about their relationship and hence, in order to protect himself, he tried to distance himself from uke and went back to his old lifestyle. This hurt the relationship even more and things starts to went down spiral. After a long painful period, uke finally had enough and decided to end it after realising he had fallen in love with someone else. To be fair, Miho is also suffering but was unable to let go of uke. As a result, they let on this toxic relationship longer than it should.