Beyond the main story bosses, Yakuza Kiwami 2 features several hidden and optional boss encounters that offer unique challenges and valuable rewards. These fights often require specific conditions to unlock or are part of longer substory chains. Defeating them is a mark of true mastery.

Notable Hidden Bosses:
- Amons: The legendary Amon clan members appear as super bosses. Each Amon has a unique fighting style and requires advanced tactics. Unlocked after completing all substories.
- Secret Arena Fights: Certain high-tier fights in the Battle Arena can be considered secret bosses, offering extreme difficulty.
- Majima Everywhere (Majima Saga): While not a 'boss' in the traditional sense, Majima's random appearances in the Majima Saga provide challenging and rewarding encounters.