The fact that Yayoi declares that there should be no romance within the members of the band. Considering three of the possible candidates for Shouichi's heart are his band members (not like you'd want a Gonda route, right?), this is brought up in those girls routes:
In Yayoi's route, naturally, Yayoi ends up having to swallow her words in front of everybody. And gets bitten in the ass for disobeying her own rule by the rest of DEARDROPS by pulling a prank on Yayoi on her first day of college.
In Rimu's route, Literal-Minded Rimu ends up with a 10MinuteRetirement from DEARDROPS when she realizes that she's in love with Shouichi.
In Riho's route, Riho quickly declares that she loves Shouichi and that he loves her back but they will not become a couple, despite acting like Sickeningly Sweethearts in front of everybody.
Riho's route again, when she reveals that Shouichi and her are dating. Of course, Everyone Can See It already, only for Riho to act shocked. And then, Rimu and Yayoi ask if Riho and Shouichi had their 'first time' yet. Thing is, your first time with Riho is with her drunk. To drive the point further, Riho does a GLORIOUS Spit Take, TWICE. You WILL FALL ON THE FLOOR LAUGHING.
About a third or a half of Kanade's route is told from her perspective. When she chooses to pursue a career in becoming a professional singer, her career isn't really off to a good start. She sings at... the kids' section at the local department store. Needless to say, her Shrinking Violet personality caused her to sing like a walrus.
Then, her manager's assistant gets Kanade a second gig with the promise that this gig has a 'nice stage', but he hasn't gone to the venue in person yet. Cue the Crowning Moment of Funny when Kanade finds out that her new singing gig is... at a strip club in-between shows. Surely, SOMEONE must have seen this coming.
Kanade: W-Well, that certainly IS a 'nice stage'...
Then there's when Kanade reveals to Shouichi that she accepted a singing job at a strip club. Being the supportive one he is, Shouichi tells her to follow her heart. HOWEVER, when DEARDROPS finds out, their reactions range from utterly shocked (the girls) to amused (Gonda).
When DEARDROPS goes to support Kanade by going to the strip club to see her sing. Their reactions to going to their 'first show' (aside from Gonda) are HILARIOUS! Gonda simply enjoys the show, Shouichi is too gentlemanly to look, Rimu is curiously watching, Yayoi is beet red the whole time, and Riho is somewhat appalled.
You gotta admit watching Chika, Kanade's littlesister giving instructions to a professional camera crew in Riho's route on how to take a good side of DEARDROPS is pretty funny.
Main route, the decisive choice during Rimu's mom and stepdad's wedding where your girl of choice ends up catching the bouquet. The girl who catches it will likely become your Love Interest. Yayoireally wants the bouquet, Kanade is visibly surprised, Rimu has absolutely no clue on what she just caught, and Riho hesitantly accepts it.