Here is the full list of all 23 World End Syndrome trophies - there are 7 bronze, 8 silver, 7 gold and 1 platinum.
Obtained all trophies.
Watched the worst ending.
Joined the Mystery Club.
Cleared Saya Kamishiro’s route.
Cleared Rei Nikaido’s route.
Cleared Maimi Kusunose's route.
Cleared Yukino Otonashi’s route.
Cleared Miu Amana’s route.
Celebrated Maimi's birthday.
Miu Amana called you a pervert 10 times.
Completed the mission "Flowers for You."
Miu Amana deleted your pictures.
Found all five colors of the Mihate Town Brochures.
Revealed Hanako Yamada's true identity.
Listened to all of Hikaru Tsukioka's radio episodes.
Received Hattori’s cod-liver candy.
Cleared the Truth route.
Had a dream about Kaori Yamashiro.
Filled in all character slots.
Cleared all missions.
Maxed out all auras.
Collected all CGs.
Read all of the TIPS.