His first appearance is in the Chunin Campaign, kidnapping Ken and reveals that he wants to destroy the 5 great villages, but escaped after a battle against the main character, Genzu and Shin and heads back to his third laboratory. He then sends the Shikigami Yanki to protect the entrance of his third laboratory to buy some time. After the Shikigami Yanki failed to protect the laboratory, Kojima then sends his guardian, Gedo Sessho Seki to protect him and resurrected the Tengu brothers as the undead.
Later, after the Jounin Campaign, Kojima sends his undead puppets to attack the Fire Village. A residential area was attacked so the Black Ops sent the main character to guard the commoners. After Hokage Yudai, Black Ops Leader Cyowusuke, and Council Leader Mongo did an investigation and confirmed that the undead puppets were sent by Kojima. Kojima invaded the town and stole the scroll that Orochi the Snake was sealed in after the Jounin Exam. Kojima's partner, Anaki, used Kinjutsu: Dead Bone Puppet to summon more undead puppets to buy them some time to allow Kojima to escape. After a couple of undead puppets were defeated, Anaki used Kinjutsu: Dead Resurrection World to summon undead ninja but Genzu stopped the other puppets with a lightning Ninjutsu attack. While Genzu is battling Anaki, the main character went after Kojima. Being persistent, Kojima used Kinjutsu: Soul Infusion to infuse the scroll into his body and used Summoning Release: Rigid Rhino and Summoning Release: Rage Bear to summon a Rigid Rhino and the Rage Bear to fight for his side. The main character defeated the Rhino and Bear but Kojima flees with the scroll.
- Level 40 - Kojima Series: The Beginning (mentioned)
- Level 41 - Kojima Series: At the Orochi Temple
- Level 42 - Kojima Series: Orochi Scroll
These are Kojima's during both the Chunin Exam and Jounin Exam at the level of 40.
- Normal Attack: Deals 150-200 damage.
- Hell Hand: Deals 350-520 damage.
- Kinjutsu: Dark Hell Fear: Deals 300-390 and inflicts Fear (stun) for 3 turns.
- Kinjutsu: Soul Chain Bundle: Inflicts Soul Chains and reduce 240 HP for 3 turns.
These are skills that Kojima used during the scenes and descriptions but not during the battles.
- Kinjutsu: Soul Infusion: Kojima used this technique to seal the Orochi scroll into his body.
- Kinjutsu: Soul Resurrection: Kojima used this technique to revive the fire Tengu and the wind Tengu as zombies.
- Summoning Release: Rigid Rhino: Kojima used this to summon the Rigid Rhino that have fire ninjutsu during Part 3 of the Kojima Series level 42 (Kojima Series: Orochi Scroll).
- Summoning Release: Rage Bear: Kojima used this to summon the Rage Bear that have ice ninjutsu during Part 3 of the Kojima Series level 42 (Kojima Series: Orochi Scroll).
- Summoning Release: Shikigami Yanki : Kojima used this to summon the Shikigami Yanki to protect the entrance of Kojima's Third Laboratory.
- Summoning Release: Gedo Sessho Seki : Kojima used this to summon the Gedo Sessho Seki to guard the inside of his third laboratory
- Summoning Release: Tengu Brothers : Kojima used this to summon the Tengu Brothers to protect the inside of Kojima's third laboratory if Gedo Sessho Seki failed.
- Kojima has his own unique dodging animation unlike other ninjas: Instead of using the Body Replacement Technique, Kojima splits into two (as purple silhouettes) and re-forms.
- He is also based on Orochimaru in Naruto; like Orochimaru he also has his own laboratory.