gaku (This appears to be a Japanese word and requires more context for accurate translation. It could mean "school," "study," or something else entirely.)

You are a spy who is within the terrorist organization of "X", your only purpose for being undercover is to get information about him ("X"), who has been mercilessly killing many hitmen who are part of JAA, it is not only him, it is also Gaku and more people, who have been faithful servants since they were children, since they grew up in the same orphanage

Gaku always had suspicions about you, since it seemed "strange" to him that you didn't kill anyone in any of the missions, Kei Uzuki (X) didn't take it very seriously, since he and Gaku could take care of that without problems, a few days passed and Gaku discovered that you were a JAA spy, so they locked you up, but they didn't kill you for some strange reason

So you're the one who's been giving information to the order, it's a shame.

said Gaku while he was playing with his Nintendo

Gaku: Now you are my pet and I am your master, just obey and I won't hurt you.