The Final Substory

Go to New Serena. Tanimura will arrive with a letter from Amon.

Prepare for the battle: ensure all characters are fully leveled, equip armor and healing items on everyone. Specifically, equip Tanimura with all three Sacred Tree armor items. Weapons will break immediately upon hitting the Amon Clan members, so they are not recommended.

Go to the Underground Parking Lot during nighttime. Find a black car and a man in a suit east of the taxi. Agree to go to the Arena to fight the game's superbosses.

Kazuya Amon (vs. Akiyama): Kazuya fights barehanded and is very fast. Start combos from a distance and close in with Slash Kicks. Use Wall Crush when you have enough Heat for free damage. When Kazuya gets low on health and starts dodging, switch to Heavy attacks and Counter Kick.

Jiro Amon (vs. Saejima): Jiro wields a hammer that causes explosive damage. Avoid his hammer attacks. Wait for him to attack, then use a Charging Finish combo. Use plenty of health items on Saejima. Jiro will periodically use orange Heat to restore his health; he can be grabbed and slammed for damage and Heat Actions. When he reaches low health, he enters red Heat and becomes faster but can no longer heal. Wait for his attacks before responding.

Sango Amon (vs. Tanimura): If Tanimura is equipped with the Sacred Tree armor, this fight is easier. Sango uses an SMG. Without the armor, dodge his bullets carefully. After draining half his health, Sango uses a second SMG and begins melee attacks. He also parries effectively; parry him into a wall for free hits and potential Heat Actions.

Jo Amon (vs. Kiryu): Initially a punch-up, Jo starts throwing grenades, including a three-grenade move that knocks you down. Dodge and attack his rear. After draining his health, use a Heat Action like Essence of Rolling. Jo will then refill his health and rapidly switch between Kazuya's unarmed style, Jiro's hammer, and Sango's SMGs. Counter hammer and unarmed strikes with Tiger Drops. When his health is very low, dodge to avoid a kill-sat laser attack. Continue to counter his attacks and defeat him.