Get your hands on Majima's massive bat as soon as you can & never ever let go.
Guide to Roflstomp the Final Boss
Reach SSS in Majima Everywhere, equip the unbreakable bat & turn on beast mode. Press attack.
Are you a busy person that doesn't have 3 hours to spend in every Kiwami boss fight?
Do you dislike having several sweaty (yet nicely dressed) men on top of you at the same time?
Grab hold of Majima's long, hard bat as soon as you can & never let go.
It's Not Tiger Drop, but
Everyone says you should learn Tiger Drop & spam it.
They're right, and it is the fastest way to become overpowered.
The problem is, you have to grind the coliseum for points. And then you have to learn the timing, which shouldn't be a problem by the time you get enough points to learn this move.
And yet therein lies the problem. By the time you learn Tiger Drop, you already know how to fight, so what's the point? Not to mention you're probably going to spend more time fighting in the coliseum than you would the bosses without Tiger Drop.
On the other hand, Majima grinds you. Constantly. You can easily max out Majima Everywhere in each chapter, just by running around town.
You Can Get It Just in Time
So, if you don't want to spend a lot of time in the coliseum, just get it on, hot & steamy, with Majima until you reach Chapter 10.
Chapter 10 removes all caps on Majima Everywhere, and it's just before the most frustrating fights in the game. Get to SSS, and he will gift you his firm, stiff, rigid bat.
Equip it, turn on Beast mode, and press attack.
That's it, you win the game.
Sometimes, the enemy will unleash an uninterruptible combo. If you want, defend it & you won't take any damage because you're holding Majima's sturdy, thick bat. This will keep your health at above 90% throughout the fight.
Or, keep attacking, you'll likely kill the enemy before he kills you, no matter how enormous his life bar is, compared to your tiny little one. Your choice.
You're Are Winner
From this point on, you get to laugh at everything the game throws at you, including the massive waves of enemies in the last chapter.
Nothing can withstand the massive penetrating power of Majima's epic bat.
You'll be like a Japanese Moses, parting the seas.
Even with lots of enemies shooting at you, your life won't drop below half before mopping up everyone.
The final boss becomes an amusement. You might want to let the hyper-amor recharge all the way through every time, so you can have another chuckle.