Akane and My Dear Joker
My Dear Joker is fought in a one-on-one battle. You will only be able to control the protagonist during this fight.
Bring as many healing items as you can during the fight as you will not have allies to heal you. Attack My Dear Joker with melee attacks to break its shield and stun it.
My Dear Joker does not have any weaknesses so you will need to resort to dealing technical damage when using skills. Attack the boss with wind skills when it is burned, physical skills when it is shocked, or nuclear skills when it is frozen for additional damage.
You can destroy the bike in the middle of the area to deal massive damage to My Dear Joker. It is also likely to stun him, allowing you to get in more hits before he can retaliate. Lure him near the bike and move towards it with Phantom Move. Use Action to shoot the bike, causing it to explode.