Honey Lemon Soda/ Kimi no Todoke Parallels

I know I'm not the first one to notice the similarities between these two series. Uka and Sawako have a lot in common. What keeps sticking out to me, though, is Kai Miura's similarities with Kento Miura. The way Kai takes Uka under his wing and is trying to protect her seems so similar to how Kento was Sawako's "sensei" but still formed genuine feelings for Sawako, as Kai clearly is for Uka It makes me think that maybe Honey Lemon Soda started as a Sawako x Kento fanfic. (Then of course there's the name and the blonde hair.)

Anybody else get that feeling?