Ousama Ranking: Yuuki no Takarabako
English title: Ranking of Kings: The Treasure Chest of Courage
Japanese title: 王様ランキング 勇気の宝箱
Type: TV
Episodes: 10
Premiered: spring 2023
Source: Web manga
Genres: Adventure, Fantasy
Studios: Wit Studio
Producers: Aniplex, Dentsu, Fuji TV, Kadokawa, Bandai Spirits
Duration: 22 min per ep
Rating: PG-13 - Teens 13 or older

"A treasure chest of unspoken courage is opened."

The special is described as a collection of shorts, showing past instances of courage and personal growth by the cast of Ousama Ranking.

(Source: Ranking of Kings Wiki)