Yona of the Dawn OVA

At a remote hot springs lodge, Yona and the team rest. The boys are taking a bath with the exception of Ki-ja, who looks troubled. Jae-ha takes this chance to tease him, unwittingly finding a mark linked to the previous White Dragon—whom coincidentally is also Ki-ja's father—prompting Ki-ja to recall their complicated relationship.

In another time and place, Son Hak and the dragons banter as they hold a drinking contest. As they start to doze off one-by-one, Zeno dreams of his past, where his abilities and experiences, both as a person and as the Yellow Dragon, are revealed.

(Source: MAL)