Requirements: Female protagonist, Kakyoin in party
When Kakyoin is in the party, talk to the shopkeep he was standing in front of before, and Kakyoin will offer to buy you a gift. You can choose between a Gold Barette, a Pearl Necklace, or Brass Knuckles. Whatever you choose will be equipped automatically, and Kakyoin's FP will go up by 1.
Requirements: Pixies, or Kakyoin/Joseph in party
At the docks near Abdul, talk to the woman looking towards the ocean and she'll explain that she dropped her wallet in the ocean. If Joseph or Kakyoin helps her, they'll get +1FP. If the protagonist helps her with Pixies, you'll get 300G as thanks and +150 EXP.
Requirements: Abdul is in the party
If you enter the sushi bar with Abdul in the party, you'll get a short scene, and Abdul's FP will go up by 1. (The FP will go up just by entering - there's no need to actually buy any sushi.)
Requirements: Male protagonist, Kakyoin is in the party, Nervousness below 4 (decided by the personality quiz)
In the marketplace, there's a woman drinking at the bar. Sit with her to raise Kakyoin's FP by 1. This will only trigger for certain protagonists depending on the number of "shy"/"antisocial" answers on the personality quiz - for example, Miracles or Wildhearts may not be able to get it.
A Small Gamble
Requirements: Abdul is in the party
When Abdul is in the party, a girl in a bunny suit will appear next to the restaurant. Talk to her, and you can bet 10G on a coin toss. Abdul's FP will go up by 1 regardless of the result.
Requirements: Jotaro is level 10 or above and is in the party
If Jotaro's level is above 10, a random encounter with Assassins x3 may occur when walking outside with him. Defeat them to raise his FP by 1.
Squid Ink Pasta
Requirements: Joseph is in the party
Purchase Spaghetti Nero in the marketplace while Joseph is in your party
Requirements: Female protagonist, no Bunny Suit in inventory
If you wait in the harbor 8 days into your journey, a bunny girl will appear in the market and offer to sell you a Bunny Suit for 5000G. There's also an extremely rare (roughly 1/800) chance that you'll get one for free by talking to the bunny girl standing by the bar. The Bunny Suit is an alternate costume that changes dialogue and sometimes causes either you or the enemy to lose a turn, like the Japanese Clothing for males. It can only be equipped when you're the only one in the party, but even then, your character will refuse to put it on the majority of the time.
Many people around town will mention a mysterious string of incidents involving an attacker who leaves behind large bird footprints, and a nervous-looking man hiding at the docks to the west. Check behind one of the pillars to find an enemy Stand user. He'll run away, but if you catch him a few times (not so easy to do, as he runs at max speed the final time, so try to get him cornered) you can begin a battle. Defeat him for -1 bad karma, +1 FP for whoever was in your party, and a Badge of Honor.
In addition, if your Stand is Wildhearts, it will chase him and bring him back when he tries to escape, starting the battle immediately.
Stand Users are drawn together...
Requirements: Defeated Utah in Hong Kong
In the room next to the sushi bar, Utah, who you met in Hong Kong, will ask if you want to battle him again. Defeat him for +1 FP for whoever is in your party. In addition, if you have less than 40 days left after beating him, he'll be walking around the marketplace, and occasionally give you something to eat when you talk to him. If you are on your fourth playthrough or up and intend to complete the Sword of St. George sidequest, this battle should be skipped in order to encounter Utah in Edfu later.
Man In Uniform
There's a man in the harbor who says he can see a man in a weird costume. Talk to the man hidden directly in front of him, on the edge of the map near the Jeep, and if you answer "yes" to his question a difficult battle will start. However, if Joseph is in the party, he'll instead persuade him to join you as an ally, raising Joseph's FP by 3 and altering events that occur later in the story.
Range: S-M. Same as the ones in Hong Kong, but they now appear in groups of 3.
Range: S. Appears in groups of 3 or 1. You can tell them apart from Burns on the map as they occasionally jump. Their AoE bomb attacks deal high damage, and can cause Blowback, and they can unleash their energy, dealing more damage, but also destroying itself in the process. Weak to Ice, Electric, and Water elemental attacks.
Range: S. Appears in groups of 1.
Range: L. All start out with HoldBack status. Can be run from in a pinch.
OPTIONAL BOSS 1: Emilio
Badge of Honor
Range: M. Weak to Fire and Light. Considerably fast at 150 Speed, though not quite so much as Chicken Shack. Focus your attacks on him. Vulnerable to berserk. Can throw knives in hard mode.
OPTIONAL BOSS 1: Chicken Shack
Emilio's Stand. Range: M. Can inflict Poison and Confuse with its attacks. Extremely fast with a Speed stat of 500.
OPTIONAL BOSS 2: Utah
Range: M. Weak to Electric, Ice, and Light attacks. Essentially the same as Utah in Hong Kong but with much higher stats.
OPTIONAL BOSS 2: Saints
Range: M. Uses Wind elemental attacks that have a chance of inflicting BlowBack. Can also summon Burns.
EXTRA BOSS: Stroheim
Range: S. Attacks with weapons like guns and grenades. You can get a UV Amplifier through a later event, so there's not really much point to defeating him. Electric attacks are super-effective, he's weak to Earth, and is susceptible to 1HKOs.