This game is kind of buggy. I noticed sometimes when picking different branches, it would count both paths. Not sure if this always happens, what makes it stop happening, or how you can fully take advantage of this... but be aware that it can happen.

Also note that some choices don't matter, when it seems like they should. Like both choices do nothing. Or both choices give the same impact. Probably just bugs? Anyway, below is what I found... it worked for me to get all achievements, so hopefully it helps you!

These are the characters... some have a bunch of different names the game calls them, so that can be confusing:
Murong Qingxue (Snow) - Childhood Sweetheart
Li Xiaoqian - The Hottie
Xia Mengting - Ex Girlfriend
Zhang Yu (Jade / Brother Yu) - Dancer
Liu Yaru - Mother / Boss
Mu Zishu - Rich Lady

Help Her - Meng Ting+, Walk Away - Nothing

Think About It - Meng Ting+, Reject - Nothing

Lift Her Up - Jade+, Turn Around - Nothing

Reminder of Exposure - Xiaoqian+, Continue Watching - Nothing, Help Button - Nothing

Incognito - Nothing, Mind Reading - Nothing, Charm - Xiaoqian+++

Long Sleeves - Snow+, Expose Navel - Snow++, Sleeveless - Snow+

Big - Nothing, Small - Nothing

Die is Cast - Meng Ting+, Did Not Happen - Nothing

Read Mind - Nothing, Do Not Read Mind - Nothing

Agree to Ride - Yaru++, Refuse Ride - Yaru+

Agree - Yaru+, Reject - Nothing

Accept Drink - Zishu++, Refuse Drink - Nothing

Go w/ Meng Ting - Meng Ting+++, Go w/ Jade - Jade++++, Reject Both - Meng Ting+, Jade+ (Note, your choice w/ Meng Ting’s path still seems to impact this overall rating when picking Reject Both)
If Meng Ting: Agree - Meng Ting++, Complain - Nothing

Mind Reading - Nothing, Charm - Zishu+++, Accept Gift - Nothing

Accompany - Snow++, Refuse - Nothing

Incognito - Snow++, Mind Reading - Snow++, Charm - Nothing

Protect Yaru - Yaru+, Keep Silent - Nothing

Tasty - Nothing, Unappetizing - Nothing

Dragon King - Yaru+, Invisibility & Mind Reading - Yaru+ (Note, if you do both paths, you appear to keep the bonus for both)

Sincere - Yaru++, Stopgap - Nothing

Give Her the Key - Meng Ting+, No Key - Nothing

I got lazy here, sorry. When you have the choice of the 6, the initial choice does not seem to have any impact, but then there is 1 or 2 choices to make... and those will have impact; I didn't take the time to measure these, since I was able to get all achievements with little manipulation of this section. Just Pick Xiaoqian and the 2 choices of hers I called out.

Accept - Zishu++, Decline - Nothing


Snow:
Meng Ting: Come and See - , Come and Accompany -
Zishu:
Yaru:
Xiaoqian 1: All Look Good - Xiaoqian++, Normal Good Looking -
Xiaoqian 2: Come and See - , Come See Costume Change - Xiaoqian++
Jade:

Ordinary Colleagues - Yaru+, Good Relationship - Nothing

Help - Xiaoqian+, I’m Busy - Nothing

Go Try It - Jade++, Decline - Nothing

Back to School - Snow++, Not Going - Nothing

Pretend to be Boyfriend - Zishu++- , No Relationship - Nothing

Travel - Zishu+, Don’t Travel - Nothing

Meet Six - Nothing, Meet One by One - Meng Teng+, Xiaoqian+, Snow+, Yaru+

Follow Yaru - Yaru++, Follow Zishu - Zishu++, Go Home - Jade+

To get this achievement, do the best choices from above. When there is a branch in options, pick these:

• Chapter 2 - Go with Meng Teng, then Agree
  
• Chapter 4 - Pick Xiaoqian, then All Look Good, then Come See Costume Change
  
• Chapter 5 - Meet One by One. Then Go Home Alone.

That should get your stats like this, and picking Zishu in Chapter 6 will get you the Mental Patient achievement:


This should also get you the good ending for all of the other 5 girls. To get Zishu's, just pick Go with Zishu at the end instead of Go Home Alone.