Getting the True End in Stella Glow is actually very easy to do, but it's also easy to miss. Here are the requirements:
- Raise Alto's affection level with Klaus to the 2nd level (so that Klaus learns the Magic Shield ability) before Chapter 8's free talk time is up.
- If you did the above correctly, a certain character will join you in Chapter 10.
- In the final battle, halfway through the fight a character will make a request of Alto. Refuse to grant their request.