Yakuza 4 Remastered

Having struggled against Jiro's ever-refilling health gauge, I'll say that pistols are a must for Saejima, unless you're really good. I had three revolvers plus three additional weapons for heat actions. Weapons break if you use them in regular attacks, but if you pop Tauriner for heat and then equip an umbrella or stun gun or something like that, you can deliver a lot of damage in a short period of time. I finally got past Jiro by emptying two guns right away to build heat, swapping to unarmed and grabbing/throwing Jiro, then delivering a heat action while he was on the ground. Those took him down to about a health bar. I then emptied the remaining gun, rebuilt heat, grabbed/threw him again, and then delivered another heat action while he was on the ground. That took him down to about three-quarters, and I then paused, popped another Tauriner, and then switched my weapons to stun gun/etc. Getting one of those right away got him out of orange heat and into red heat, at which point he was no longer healing, and I only needed one other heat action to put him out of action for good.

For Akiyama, I'd recommend filling on Tauriners and just luring him to the walls for Essence of Wall Crush. For Tanimura, if you have the Sacred Tree Armor you can wait for him to begin his spray-and-pray animation and deliver XXXYY combos very effectively, then parry him repeatedly into a wall once he's close enough. For Kiryu, you'll want healing items and possibly the pistols, but I beat Jo with a few well-timed Tiger Drops and a whole bunch of Komaki Parries. Just watch out for the Orbital Laser blasts, as CyricZ mentions in his guide.

Just in case some people are confused, you only need to complete the protagonists’ substories and the Amon one, no need for the hostess substories.