Sasai Yankus is a member of the Chryse Guard Security First Group and a minor antagonist in Mobile Suit Gundam IRON-BLOODED ORPHANS.
He is voiced by Masashi Nogawa in Japanese and by Keith Silverstein in the English dub.
Sasai Yankus and the rest of CGS were hired to provide security to Kudelia Aina Bernstein, an advocate for the Mars Independence movement. When the CGS base was attacked by the forces of the Gjallarhorn Mars Branch, Sasai and the rest of the adults of the First Group stayed safely in the base and let the "Human Debris" of the Third Group do most of the fighting. After the battle, Orga Itsuka, leader of the Third Group, protested to Haeda Gunnel for letting the members of the Third Group die for them while doing nothing to help, but Sasai and the First Group simply beat Orga up.
However, at night, while the First Group were all sleeping, the children of the Third Group staged a revolt against the adults of CGS and tied all the members of the First Group up. After Haeda was executed by Mikazuki under orders from Orga Itsuka, Sasai attempted to charge at them but was shot by Mikazuki too.