I've looked for the rest of the chapters everywhere I I can't find it 😩 I've been waiti...

You can buy the official book on amazon jp
https://to-ti.in/product/strange_top

i thought it was a oneshot

"Strange" is just one of the oneshots that's part of this collection, there are 7 oneshots in total:
1. STRANGE
2. CONNECT
3. BRIGHT
4. FRIEND first step / step & go
5. PRETTY!
6. MOVE
7. AFTER

to add to this you can buy it on Renta jp aswell https://renta.papy.co.jp/renta/sc/frm/item/182889