Human :)'s activites

Does anyone who has read Shiori experience know who the person they referenced the manager of the 27 group off of was?? Bc I swear i’ve seen him before somewhere but I don’t know much about anything relating to musicians or about the people that work in the music industry ╥﹏╥

This manga got similarities yet the plot is quite different from each other. My Fav! This is in a random order. I will update in as I come across more similar manga which I like. 

EDIT: Thank you! I never thought the list I created cause I was bored will get followed by 3k+.. Glad to know we got similar taste in manga~ :)