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