Yui Hirasawa is starting high school and she is looking for a club to join. One of Yui’s childhood friends asks her “politely” to join a club because it is important.
At that same time, Ritsu Tainaka tells Mio Akiyama that she is going to join the light music but all of the members have graduate and the club is going to be abolished by the end of the month if it does not have at least four members. Mio prefers to join the literary club but Ritsu rips up Mio’s club form and forces her to join.
Ritsu and Mio end up in the club room waiting for people to join. Tsumugi Kotobuki walks in asking for directions to were the chorus club but gets suckered into joining the light music club by a sad story that Ritsu made up. A week goes by and they still don’t have a forth member, the girls make up a flier to get people to join.
Yui notices the flier and decided to join the light music club but the thing is that she can only play the castanets. She starts regretting joining the light music club because she thinks that she is not good enough.
However she starts thinking what would the reaction of the club members be if she said if that she doesn’t want to be part of the club.
Yui Hirasawa is one of the members of the light music club, and plays a Heritage Cherry Sunburst Gibson Les Paul Standard electric guitar. She does not get good grades in school, though properly coached, she can achieve astounding results, and is easily distracted by trivialities. Yui has a very easy-going nature but when hyped, has incredible concentration, though this is only limited to one subject at a time. She will totally neglect any other things in the process, to the point of forgetting anything she has learned beforehand. Her surname is taken from P-Model guitarist Susumu Hirasawa.
Mio Akiyama is a shy girl in the light music club who plays a left-handed, 3-Color Sunburst Fender Jazz Bass with a tortoiseshell pickguard. She originally intended to join the literary club, but was forced into the light music club by her childhood friend Ritsu. She gets excellent grades in school, but is bad with listening to stories involving painful experiences, and will assume a fetal position whenever something gross is brought up. While she can be strict sometimes, she gets embarrassed easily, and cites that she chose bass since it is not in the center of attention like with guitar.
Ritsu Tainaka is president of the light music club and plays a Yamaha Hipgig Drumset. She has an ambiguous personality, and often has trouble with forgetting about important club activities and announcements. She says she chose to play the drums because they are “cool”, but she has trouble playing instruments which involve intricate finger movements. She is a childhood friend of Mio and will often tease her whenever she’s cowering from something. Her surname is taken from former P-Model drummer Sadatoshi Tainaka.
Tsumugi Kotobuki is a wealthy girl with a gentle personality who plays a Korg Triton Extreme 88 Key keyboard in the light music club. She has played piano since she was four-years-old, and has experience in winning piano contests. She is the daughter of a company president, and her family has several villas in various places around Japan. When Yui goes to buy her guitar, Tsumugi is successfully able to drive down the price. The reason she gives for her success is that her family just happens to own the store. She often brings confectionery to the club room, along with a tea set which is kept in the room. She originally intends to join the choir club, but joins the light music club after receiving an invitation and encouragement from Mio and Ritsu. Her surname is taken from former P-Model keyboardist Hikaru Kotobuki.
Sawako Yamanaka is the adviser for the wind instrument club at Yui’s school. An alumni of the school and a former member in the light music club, she does not want people to know she wanted to be in a heavy metal band. She is forced to be the adviser of the light music club, as Ritsu blackmails her after the girls learn of her past, though it is unknown whether she stopped being the adviser for the wind instrument club as well.