MUSHIKAGO is an automatic penetration testing tool using game AI, MUSHIKAGO focuses on the verification of post-exploitation. A post-exploitation is an attack that an attacker carries out after invading the target environment. By focusing on post-exploitation verification, we can understand how far an attacker can actually penetrate and what kind of information is collected. MUSHIKAGO uses the GOAP (Goal-Oriented Action Planning), which is game AI commonly used in NPC (Non Player Character). To using GOAP, we can flexibly change the content of the attack according to the environment like NPC, and mimic the attacks by real APT attackers and testers. The operation and verification results of MUSHIKAGO can be checked on the dedicated web page. Moreover, MUSHIKAGO supports ICS (Industrial Control System), and can be used for penetration testing across IT and OT (Operation Technology).