Volume 9

'''BanzPSI! Tsundere Grandpa''' (万Ψ！ツンデレおじいちゃん Mansai! Tsundere Ojīchan) is the 9th volume of the Saiki Kusuo no Psi-nan, also known as The Disastrous Life of Saiki K., manga series.

Cover Conversation
Kuboyasu Aren: If you are bored, why do we not fight? Saiki Kusuo: If you are bored, why do you not buy this manga.

Alternative Cover Conversation
Aren: If you are seeing this, it means you are ready to fight, right? Kusuo: It means they bought the book.

Character Comment
Aren: I am Kuboyasu Aren, the 12th general of the Ibaraki gang, “Espers.” I plan on completely destroying you hands down in this fight. Nice to beat you!!

Chapters
Note: Chapters with the label have NOT been adapted into the anime series.
 * Chapter 85: The AbPSIlute Worst Employee
 * Chapter 86: Ready To Go! Runners PSIart!
 * Chapter 87: Teruhashi ReviPSIts the Saiki House
 * Chapter 88: Press Play! A "Making Of" PSItoryPsi icon.png
 * Chapter 89: Transform! Super PSIze
 * Chapter 90: The Peak Of ExPSItement! Karaoke Party
 * Chapter 91: PSIpporting Re-Education
 * Chapter 92: BanPSI! Tsundere Grandpa
 * Chapter 93: Welcome to the PSIculded Theme Park
 * Chapter 94: PSIjian! Parting with the Grandparents
 * Chapter 95: The PSInnacle of the Golden Age of Heroes! A Fun Party GamePsi icon.png

Summary
The Saiki family decided to visit the mother's parents' home during spring break. They are greeted by a gentle grandmother and a very difficult grandfather! However, this silent and unfriendly grandfather has a cumbersome secret that only Kusuo knows!

Character Profiles

 * Saiki Kumi
 * Saiki Kumagoro

Author’s Comment
"In the middle of meeting with my editor, I was worried about this character’s hair color. When I tried asking “what should I do? Would green work?” My editor suddenly said, “my mother dyed her hair green.” ...huh!? It is green!? Why? Was this recently? ...ever since middle school!? I have known you for 8 years but this is the first time I am hearing this!? Why!? ...I had no idea...normally you would tell someone about something like that, right!? So in the end I gave Kuboyasu purple hair."

- Asou Shuuichi