Shops: Bunker and others
Chips with lower level combinations equaling a single +8.
Upgrade materials you might still be missing after getting all the chests and quests in the first two routes, even with double drop rate equipped.
Powerup Part L: One acquired in The Tower during route C, the others for defeating optional bosses: see Golden Rabbit in Amusement Park and Emil's Determination quest in City Ruins: Commercial Facility.
"Critical +" weapons
Weapons with "Critical +" effect (when upgraded to at least level 2).