Item Development, also called Item Synthesis, is a feature in both Hyperdimension Neptunia mk2 and Hyperdimension Neptunia Victory that allows the player to develop anything from items to weapons and accessories. You can develop new items by synthesizing ingredients. To develop an item, you need the ingredients and coinciding Product Proposal. Also, in order to develop certain items, you need a certain Lily Rank. Item Development requires Product Proposals and materials. Product Proposals can be found in dungeons, looted from monsters, or purchased in the store, whereas materials can only be found in dungeons or by defeating certain enemies. Lily Rank also influences synthesis due to some items requiring a specific Lily Rank between two characters in order to perform synthesis.