Here is the full list of all 31 Guilty Summer Kiss 2 - there are Bloody Secret achievements.
See the fight of Nakahara sisters
Become responsible for Miya's reclamation
Not to step on the shoelace when running away from Miya
Get into someone else's body
Hug Lisa
Show Lisa the photo of Arisu
Say "No" to Rei
Be saved by Miko
Let Rei live in your house
Be called boring
Betray Arisu
Put 100 likes to Hisano in underwear
Put 100 likes to Lisa in underwear
Put 100 likes to Miya in underwear
Find Arisu
Agree to help Hisano for money
Find out what heterochromy is
Be killed by Rei
See Lisa betraing her mother
Talk to Miko all night long
Not to go with Miya to the lab
Prefer Lisa to Miya
Listen to Lisa singing
Kiss Lisa
To mix up Lisa and Miya
Have a successful date with Lisa
Find a new body for Hisano
Die for Rei's sake
Be seduced by the headmistress
Tell Miya you love her
Prefer Miya to Lisa