Neplunker is an optional dungeon in Megadimension Neptunia VII found by scouting in the Hyper Dimension. It cost 2500 credits to build a route to it. Finishing this dungeon gives one the Hyper Booster which is useful for breaking all destructible objects. The dungeon is difficult but can be made significantly easier with the flag items unlocked in the New Game+.
The following items can be found in the dungeon. Items in the treasure chest can only be obtained once. Numbers are marked on the map to denote those treasure chests.
Destructible Object Items
1) Tulip x3 (Neptune's Attachment)
1) EnergyMate x1 Defeat Giant Ghost without ever restarting