Trying to find this manga I read a long time ago where the schoolboy MC's "mom" appears to be an average guy-looking. Pic related is a close resemblance to how it appears in my memory. The MC acknowledges the oddity, but still refers to the character as "mom". The first chapter is about how the "mom" has to show up for a parent-teacher meeting, I think there's a point where the "mom" suggested that they would put on a comedic disguise, then later the MC has to introduce to the teacher that they're his "mom". MC has white/blond hair I think.