It's more likely that MC is denial rather than dense, He kinda knew about FMC intentions but won't acknowledge it. Hope there's valid reason for his actions, even reason like he didn't want to ruin childhood relationship will fine.
After I read the manga I become curious about author live so I searched on Google, turn out she's 23 this year, she's very young and I thought this story is dark enough then I found out her video debut title was "what happen after she do it with her beloved teacher in middle school" something...
For me romcom harem story should be like this, it's cute, funny, a little bit drama here and there make is better. When other harem stories resulting other parties to ger heartbroken, this story doesn't have battle shipping and every one happy.
Apparently all the remain chapters here all gone so I read it from another site. I thought this story will end in tragedy, thankfully it's end with happy ending.
Overall it's good story, 9/10 for me.
This is one kind of comedy manga that have solid plot with the comedy that unexpectedly funny. Such a shame that I only found it 3 years after it's ended. This is such hidden gem, if you like gintama you'll like this one.
This is one of the best manga that I ever read, the story is well written and the author didn't stretch it too much like other romance manga, it's just perfect.
For me it's,
10/10.