Mizuhara Chizuru is not a scumbag. The male protagonist chose to follow Mizuhara and Asami secretly, and the male protagonist happened to hear the two of them talking. Asami first praised Mizuhara's acting skills, and then accused her of her faults. Asami said that it was because of this form of renting girlfriends that the male protagonist was unable to get a real girlfriend.
Shui Principle questioned Asami's feelings for the male protagonist, defended the male protagonist, and hoped that Asami could face the male protagonist's love for her in the future life. The male protagonist on the side heard the conversation between Mizuhara Asami. From that moment on, he understood Mizuhara's gentleness and kindness from the depths. It was from this moment that he realized that the person he truly loved was Mizuhara.
At the end, Suwon directly asked the male protagonist what he meant, in order to confirm his true feelings. Unfortunately, the male protagonist never dared to admit it because of shyness.
The ending of Rent-a-Girlfriend
The male protagonist did not end up with anyone. In fact, the male protagonist wanted to confess to Ruka, but something unexpected happened in the middle of the confession. The male protagonist's entire mind was attracted by Mizuhara and Asami who were passing by, which ultimately led to the failure of the confession. When the male protagonist heard Mizuhara Asami's conversation, he realized that the person he truly loved in his heart was actually Mizuhara.