Kanon also feels a lot more relatable than Honoka and Chika. Tho do note that instead of making the "Determined Overly Genki Girl" the MC, they just put that trait into Keke so that kind of character is never really gone. Personally, I prefer Niji's Yuu over all the protags.
The author states that Ayumu did not steal Yuu's phone, she merely had a replica of it made for some wholesome play with blocks, such as mounting the replica with her own phone in her spare time.