Dohna Dohna:Items

Badges
Badges can be equipped and unequipped to a character. None of them can be bought and all of them are unique. The following table can help you determine where you can obtain them.

Base upgrades
Base upgrades are mostly used for your prostitute management. It can be useful to upgrade your base for more TP actions or for more prostitute rooms early on for the utility it gives.

Consider waiting until you have at least a couple levels in some of these before expending your LKS/TEC/MEN items as well. This is one of the reasons it's better to sit on your prostitute consumables early on.

Battle consumables
Use battle consumables to restore health or mana to your characters, or to deal damage/debuffs to enemies.

Party upgrades
Party upgrades can be used in your base to raise your character's stats

Like weapons, these do not affect your characters' base stats. So these will not contribute to stats per level growth. Feel free to save them up, it will be no less efficient to use them later in the game.

Prostitute consumables
Prostitute consumables raise their main stats or give them positive statuses. Other than pills, which are crucial for your more important prostitutes, consider saving the LKS/TEC/MEN items until you have good base upgrades.

Trivia

 * Each level of the publications of 'Tech-G' has a characters from the Rance series on its cover. (Hanty, Kanami, Feliss, Rola, Sill, Satella - I believe, some of them are a bit hard to make out on the small covers...)
 * There are a number of badges in the game code that were not implemented in the final release. It appears AliceSoft decided that the planned Range modification mechanic was too confusing, while the herb 6 badge was cancelled and there were not really any buffs to buff for skill set (b), so that was cancelled as well.