Find Jaster part 1

So far, you all know me from the previous post. This is quiz to find me.
Instructions:
a. don't cheat
b. be honest
c. choosing options
d.to get clues, read all my post

Blaze:
I'm Jaster's friend. I may have discovered that Jaster is missing. Let's go to find him. I have found some clues.

Clues:
1. A pair of blue waves pajamas.
2. Mystery Quest series from 1 to 20
3. Dirty set of uniform
4. Mystery Quest 21 half way making
5. His school examination backpack

Let start with the Mystery Quest 21 book. "Johnny, you may have killed Sulian as a spy but still a spy from our dorm!". No clues found. Let's check behind. Insert 20 sen for war. Blah, blah, blah. Not good. What's next?

Selections:
1. A pair of blue waves pajamas.
2. Dirty set of uniform
3. His school examination backpack


1. A pair of blue waves pajamas.

Blaze:
What could we do with it? Wear it?

2. Dirty set of uniform

Blaze:
We could check the pockets. Ah ha! A key! It says here the key is use to open the "Mystery kit". Must been his bag.

3. His school examination backpack

Blaze:
Let's do this!

To open the bag find or wait for Part II