Here's a step-by-step guide to get all endings for those who want to speed-run or are having trouble getting all the endings ^^

------------------------------

Warning: This post contains slight spoiler.

NOTES:

• The TRUE End only unlocks after finishing all Good Endings and Best Ending.
• There are multiple ways to get all endings, this guide only covers one of them.
• After TRUE End unlocked, it will appear as [Extra] in Main Menu.

------------------------------

START NEW GAME

Bus Stop

-  The Bar.

The Bar

- So cool!
-  ...Just a little scritch-scritch...
- What's your ideal type?
- That's so nice of you...
Save slot 1
- The Bookstore

The Book Store

- Who am I kidding? Absolutely smash!!
- Well, I don't dislike it...
- Better stay out of it. That's bad news.
Good Ending 1 - Unlocked
 Load slot 1
- The Library

The Library

- Who am I kidding? Absolutely smash!!
- You seem really mature.
- You're still cool, Chongyun.
- Promise to bring it tomorrow.
Good Ending 3 - Unlocked
Load slot 1
- The Coffee Shop

The Coffee Shop

- Sorry, we're on a date right now...
- I'm totally fine with it.
Save slot 2
- Mm... Ehhh... Maybe...
Good Ending 2 - Unlocked
Load slot 2
- Smash 100%

Hotel

- I thought you were really attractive.
- Probably... not for a long time.
Save slot 3
- I didn't mean to deceive you!
- Tired...
Good Ending 4 - Unlocked
Load slot 3
- I mean--I like you! Seriously.
- Excited...?
Best Ending 5 - Unlocked
TRUE End - Unlocked