In my attemps in this game to go for dont have sex before date scene i tell you, you cant , you have to have sex with Yuu to obtain that scene.
Trying to make this happen i will write a guide to describe the differents relationship status that i see that you can have with Yuu.
You can have 3 relationship status with Yuu: Virgin status, Sex friends status, Lover status.
Virging status can be locked at your choice (beware you can miss lover status) and can go to Sex friends status locked or not locked, Sex friends status can be locked and can go to lover status only if not locked.
You can miss Lover status and stay locked in Virgin Status that can go to Sex friends status locked.
The condition to miss Lover status (and Bloomer scene) is to dont have sex with Yuu before the sunday free event this will make you to not be able to unlock the Date scene to go to Lover status and not be able to unlock the Bloomer scene so you will miss two scenes + scene 14 and be locked in Virgin status that can go to Sex friends status locked.
You can stay in Virgin status forever and rise her like for you, only masturbate Yuu and ask Yuu to give you fellatio, she will not lose sexual satisfaction, you will gain less money.
You can stay in Sex friends status forever only dont trigger the sunday free event and if you trigger it dont buy the casual date outfit, you can rise her like for you by masturbate Yuu or having sex with her, she will lose sexual satisfaction if you dont have sex with her, she will complaint if you dont use a comdon, your salary will come with a bonus.
In Lover status you can rise her like for you more easy if you creampied her, she will lose sexual satisfaction if you don have sex with her, you will have a new mouth option in your touch options, your salary will come with a bonus, your room will have more items on display and the BGM changes.
Tip: When she give you her virginity make her cum three times before penetrate her this will make her to stay in permanent arousal state and give you a diferent dialogue line when you penetrate her, only go for the shallow and slowly option and she will tell you something nice after.
* Edited to make some things clear.
