Bocchi the Rock! Side Story: Hiroi Kikuri's Heavy Drinking Diaryぼっち・ざ・ろっく！外伝　廣井きくりの深酒日記 ; Bocchi the Rock! Gaiden: Hiroi Kikuri no Fukazake Nikki ; Одинокий Рокер! Спин-офф: Дневник пьяницы Хирои Кикури ; Bocchi the Rock! Ngoại Truyện: Nhật Ký Say Rượu của Hiroi Kikuri ; Bocchi the Rock! Ngoại truyện: Nhật ký say tít mù của Hiroi Kikuri

Kikuri Hiroi (25 years old). She is a "genius bassist" who leads the indie band "SICK HACK", and she loves alcohol. She often gets drunk and breaks the equipment of the live house, so she seems to be short of money. She lives in a 52-year-old apartment without a bath, and sometimes borrows showers from her friends and acquaintances. She is regularly attacked by anxiety about her future, which she counters with a "happiness spiral" with the help of alcohol. What is her daily life like...?!