Ah - I'm assuming the hover system won't work for mobile - don't test it myself so wasn't aware of the issue.
Here's a list of all the events you have to complete:
- Saori - Tether
- Ami - Buckle
- Nia - Into Motion
- Rin - Metamorphosis
- Natsuki - Good Boy
- Sakura - So, This is Me
- Kirei - Nothing to Feel
- Yuna - Sisterly Duties
- Kasu - Two of You
- Takane - Life-Support
Hope this helps, and will think of a way to show this info in mobile :))