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