Ryūji Saeki/Plot

Border Enlistment Arc
Saeki is mentioned as one of the eleven Fūjin candidates by Jin for his Black Trigger.

B-Rank Wars Arc
For much of the most recent season, his squad (along with Katagiri Squad) went scouting for potential recruits outside of the prefecture.

However prior to the Final Round, they came out and was briefly shown with Uno as he called out to Satomi.

A-Rank Squad Evaluation
He comments that Yuba's presence would ensure that the squad will "run a tight ship" for the first phase, not long after he asks Kusakabe if Kuruma's relative slowness be fine if the squad is careful for the second phase.

Phase 1
He was shown happily reacting to Ikoma and Kon's dinners and wishes he could eat the food while also commenting how cool they are.