Innocents are monsters that power up your character stats that live in Disgaea 5 weapons and every other type of items even 1x use ones. They appear randomly in items gained on maps, or ones stolen from enemies or can be farmed once tamed in the innocent shop.
Innocents never appear on store items bought at the base, but do randomly show up on items in the item world shops every 10th lvl or on random item room shops. And what type of innocent that appears on an item is random.

The Types of Innocents are Green unique, Yellow subdued, and Red undefeated. They always have the words innocent over there heads in the item world. once ko'd there lvl doubles by default. 1-2 2-4 ect and sometimes you can talk to them on item worlds every 10 lvls once ko'd.
Unique Innocents are always friendly and have 1 unique bonus only. They can't be fused and can't be moved from item to item. Some are on weapons automatically and the rest are gained from defeating Item gods every lvl 100 in the item world. Each weapon/item can have only 1 Unique on it at 1 time.

The Green innocents are trapped on the item they unlock on. Yellow Innocents and Red Innocents and can be moved to and from items and the warehouse freely. But only subdued Yellow innocents can be fused together with the same type to increase their lvl. Innocents can be bred at the Innocent shop in the Innocent farm. As you can see from the image combo innocents can be gotten by farming also.

You unlock the innocent farm in chapter 9 by unlocking Innocent Aid Squad. Depending on Squad level, there's a chance for Innocents at the farm to increase their lvl up to 7%. So I suggest maxing out prisoner lvl of this squad(and hunter squad) asap. Innocents stop growing when they have a star, and because fusion favors higher lvl always fuse a higher starless innocent with a lower lvl star for bigger growth.

Red innocents are always hostile when first obtained. They cannot be fused and have their stat bonus reduced. They can be moved from item to item but need to be ko'd in the item world to fully unlock them doubling their level making them Yellow. You are then able to combine them or be bred in the farm. Farmed Innocents are always born red unless you unlock a Innocent farm squad ability.

Sometimes you find a Yellow Innocent on the farm with a star before Max level. Or Red Innocents on items that have a yellow star on them already. This means that the Innocent will not gain levels on the farm and must be removed by combining it with a higher level Yellow of the same type of Innocent without a star together. If its a Red Innocent with the star it still needs to be Ko'd Yellow first then fused. It must be fused with a higher level Innocent without a star or the star might remain.
2 Yellow Innocents with star will combine but even if one is higher level then the other the star will remain also. This can be misleading and a pain when you are starting out. If however you fuse 2 Yellows together with stars or not and exceed the Max Innocent level you get 2 Innocents. 1 with the level Maxed with a star and 1 with the remaining level balance, without stars on them.

Btw The Innocent Capture Squad once leveled can double the double level effect of red monsters on k'o to speed up the farm process. Then breed the higher the lvl innocents in the farm to raise the level of the produced offspring.
All innocents have a Max level and will no longer fuse together or lvl up when reached but they can still be bred in the Innocent shop. Each character can have whole stacks of the same Max lvl innocents, and still raise the stats or boost gains. But a few innocents will not boost past a single fully leveled innocent per character. for example Statistician total max lvl is 900 and total bonus per single character is 900. Which is the max fusion lvl of that innocent type. I'll mention the character max later on per innocent type.

These Innocents are common and stacks can be used multiple time per character. The best method to farm this type is combo them until you get 2 of the same at lvl 50,000 and then breed them in the innocent shop farm. A quicker way to combo the initial 2 needed for the farm is to transfer the Red Innocents to be farmed on a mint gum or other low lvl item like a thimble and set the item route at lvl 10 to innocent route. Then use the Innocent squad to ko them use an item exit then fuse and repeat.

Innocents that raise 2 stats can't be bought or found on items. You have to farm them to be able to get them. Take 1 of each you wish to combine place them both into the farm and then do some battles then check if a combo innocent spawned. when you have 2 of the same start farming them like regular unti you have 2 of the same at max lvl and repeat. Thes also have no limit to how many can be place on a character as long as you have space in the item that is. I like to make sure i have 2 of each ready to breed in the innocent warehouse at all times.

Now's where you can see limits per character. The max stat is 1% per lvl max innocent level is 100 because it inflicts 100% chance of the status ailment. Then if you place more than 1 fully leveled innocent per character you waste the space as you can't have more than100% chance to inflict the ailment per attack. These stats are really useful for evilities that increase damage or deathblow to an foe with ailments.

These Innocents protect against statuses. Like the offense the defence lvl caps at100% and only 1 stack of 100 will work per character. These are worth it against various stage effects and enemies that use ailments. They don't combine, but you can breed them in the farm.

These Innocenss are useful to boost up magic attack defence, or ad a 20% boost to a character who is really weak against a weapon type. Unlike most other resistance type the weapon resistance caps at lvl 20 on the innocents and only 1 stack of each 20 will work per character. This is useful for when you see your character has a negative number in their resistances. A regular number means they are strong against that type of attack. So a -20 in fist means that they take an extra 20% damage when attacked with fist weapons. A 0 mean no added damage or resistance to an attack. A 25 means 25% of that attack type is blocked.

These stats are by far the most important in the game for leveling up characters. Unlike in previous Disgaea games you can't throw unlimited Statisticians on items. There is a limit to how high any character can be buffed. The best way to get this is to buy item you see that have any on them them and then combine them until you have 2 fully lvled stacks and then leave them in the farm untill all character have 1 fully lvled stack. it is very import for you to have lvled up the innocent squad to be able to have subdued innocents bred to speed the process.

There are 51 different Unique Innocents 46 in the item world and 5 true uniques only found on rare items but every weapon type has and elemental Innocent. For example The Red ATK Monster Weapon Crab Pincer Water comes with The Unique Freezer Innocent. There are also Fun Type weapons gained as gifts and they also have a Unique Innocent The Fist Fun Weapon Pie comes with the Ambusher Unique innocent.
Unique Innocents can also be gotten randomly from defeating an Item God on each 100th level in the item world. It's fixed so you can't exit on lvl 100 with a Mr. Genecy after ganking the Item God and get a unique innocent. But you can go to level 100 steal a fun weapon off a Item God a Leave and come back for another. So you will be going to lvl 4600 at least to get 1 item all the uniques. Fun Weapon rewards come with 1 unique innocent they are powerful and not worth much HL so hang on to them. FYI Unique Innocents are always active on both weapons and all 3 Defense items at the same time.

I really would look out for some fun weapons as they can help with the grind and work even in the second weapon slot. The Chopstick Gun weakens a foe leaving 1 hp for a weaker ally to finish it off. Leeks are great for fighters as it increases counters. The Kitty Paw Stick is great for getting items off of foes you might not be able to steal from. The Megaphone is great for farming shards with a Sage as it captures foes, and finally, The Raised Flag increases stats at lvl up so make sure to get that. I hope you like this guide and it helps you all out. Till next time Take it easy.