Silver Diamond (シルバー ダイヤモンド, Shirubā Daiyamondo) is a Japanese manga series written and illustrated by Shiho Sugiura.
[2][3] The story starts with a man (Chigusa Senrou) who tries to assassinate the prince of the Amato Empire and fails.
Rakan, a high school student who lives by himself, returns home from school one day to find Chigusa lying unconscious in his garden, carrying a gun made of wood.
Chigusa recognizes him as a "Sanome" and decides to protect him to later bring to the Amato Empire to defeat the prince.
When Rakan learns of the state of the Amato Empire and meeting its so-called 'prince', he forces Chigusa into allowing him to come and help stop their world from being destroyed.