Sword and Fairy: Together Forever

Your first chance at this happens early in the game. Once Qingshu gets back home to her grandpa's sect, you will eventually be tasked with heading to a special tree in order to feed a spirit fruit to your bird companion Qiaoling. You will be shown a tutorial on how to feed your spirit beasts and make them level up, which provides boosts to the character they are bounded to (unless anyone who has completed the game can say otherwise, it seems only Qingshu can have one equipped).
After you've given Qiaoling this mandatory fruit, you can interact with the 2 bars on the bottom right of the screen to improve one of Qingshu's stats. It might be possible to resume the game without tweaking the attributes bars but every little bit helps when it comes to having increased HP or MP so be sure to regularly check on your Spirits to feed them.