Communication is the key, but a lot of people lack it. Aki was very insecure, but he gave it another try & understood why it was wrong to doubt in the first place. I can see why it's really annoying to watch happen, especially when authors make it a common trope. But taking Aki's personality in mind, along with the things he went through in his past relationship. I get why he wasn't trusting & why he couldn't say the things on his mind (his last relationship didn't really make it comfortable for him to do so either). Some either embrace the good (new) aspects in their relationship or back away out of fear of thoughts like "when is something bad going to happen." Like you said, Aki just couldn't do it. But i'm glad he was about to change the way he thought.
Eh, not gonna bother reading this one, it seems all the honest comments are getting downvoted, people seem to take art style and fluffiness of the manga too seriously and let it overpower the horrible plot and character development, so it doesn't seem BAD to them, but in reality, it's just a quick underdeveloped mangas with nice art and clique moments.
this manga didn't make me feel anything. it only made me feel angry. Characters don't seem fully developed at all and the uke was pissing me off because he never spoke about his insecurities with his lover which lead to a dumb fucking time period of 4 months where he was just being cowardly. He was so easily swayed by his ex and chose to believe him instead of his actual boyfriend. I like the stories from this author but not this one.