I've recently played through the prologue and while I started out with disliking Gaku, he actually really grew on me much like all of the other characters. Like he brings just enough wholesomeness to the whole group where I actually started appreciating him!
But after the prologue, the first route I completed was the Slasher Route (especially the Zombie endings) and OMG, he SUCKED. Like they just took out all the positive traits from him and dialed up every negative traits and dropped his IQ to that of a toddler. And it just ended that way too without any redemption.
Next I played through Route 0 and I guess he was fine there tho can't say I liked him as much as I did in the prologue. Then I played through a few routes where Gaku had died (like Conspiracy and some part of Mystery)
And now I'm playing through Box of Calamity Route and he's being super annoying again (heck even in universe) by having almost all his lines be just mentioning the curse and blaming people.
(Without major spoilers) Am I just by chance playing through routes where he sucks (or is dead) or is Gaku kinda just poorly treated by writers after the prologue and there are barely any good moments from him again?