Matt Bird writes all sorts of nonsense, but he dedicates a large chunk of his time to writing game walkthroughs.
Like any good RPG, Ni no Kuni requires that you level your characters. Without levels, you'll be trounced on by stronger enemies in the game, and that… that just wouldn't be a fun game. Unfortunately, even in a game as fun as Ni no Kuni, grinding can become a bit of a tiring slog after a while.
Fret not. There are three areas in the game where you can earn massive amounts of experience points with relatively little effort, and all three feature enemies from the same evolutionary line: the Toko branch.
What Are Tokos?
Tokos are squat, fuzzy creatures that look like they're straight out of My Neighbor Totoro. They're generally harmless creatures, and will spend most fights trying to get away from your party. Manage to kill one, though, and you'll earn a ton of experience for your troubles. There are five variations of the Toko line, three of which are fantastic for levelling.
The first is Toko, the base creature. Tokos are found on Swan Island, to the northeast of the Summerlands (Ding Dong Dell). You can access this island chain when you first get the Sea Cow, though it's not advisable to challenge the monsters here until your familiars are in at least their mid 20s. The island is small, so you don't have a ton of space to move around, but persistence will eventually pay off.
Beating a Toko will earn you 2,000 experience apiece, which should blow any other experience amounts you earn at this point in the game out of the water.
The second is the Tokotoko. Probably the easiest of the three to find, Tokotokos are located in Billy Goat's Bluff, the path that stretches south and west of Perdida. You can get to Billy Goat's Bluff as soon as you have Tengri, though you won't be able to access Perdida until you get a key item from Hamelin. The enemies here require a team in its mid 30s to early 40s for easy battles.
Tokotokos will earn you 8,000 experience apiece, a massive amount at any point in the game and typically only rivalled by boss fights.
The third is the Tokocold. Tokocolds will appear in the Ivory Tower, and it's entirely possible if you've beaten the game that you've already run into a Tokocold or two. You can find them anywhere, though the wide hallways on the second floor are the easiest places to search. Your level should be in the 50s, at the very least, to challenge the Ivory Tower.
Grinding a bit to get there is worth the effort, as Tokocolds are worth a whopping 24,000 experience, by far the most you'll get from any enemy in the game (more even than you get from the Guardian of Worlds, and it's a super boss).
Two More Tokos
The other two Tokos are the Docotoko, a third-tier metamorphosis that doesn't appear in the wild, and gold Tokos from the post-game Vault of Tears. Gold Tokos offer up a ton of guilders and almost no experience, which, while not bad, isn't nearly as helpful in the post-game as heaps of experience.
Sounds pretty sweet, doesn't it? Your levelling woes are over? Not quite. Killing Tokos is not so simple as killing other enemies.
How to Find Tokos
The Toko line is both rare and skittish. If you luck out and find one on the world map it will run, and it will run fast. Tokos can also be encountered by engaging other enemies from the same region in combat, though the chances of finding a Toko among their ranks are slim - and you have no chance of running into a magical two Tokos that way. Oooo, mass experience.
Your best bet for hunting Tokos quickly is to combine the Veil spell, acquired from Horace in Perdida, with resetting the game. If you want you can wander the fields until a Toko appears, but if you restart and reload your game on the field you'll stand a good chance of seeing a Toko nearby. Once you do, use Veil to mask your presence and rush the poor thing. You'll catch it off guard and get in a round of attacks before it can flee.
Don't have Veil? It's still possible to catch a Toko by surprise, and you very much want to catch them by surprise. Simply stalk the Toko with caution. Watch which way it goes from a distance, not getting so close that you spook the beast. Once it's facing the complete opposite direction you're coming from, dash up and catch it in the back. If you do accidentally spook a Toko, pull back and give it some room to breathe. You can't outrun these things, and they disappear if you freak them out for too long.
How to Kill Tokos
One way or another, you're now in a battle with a Toko, hopefully with a full round to attack without the Toko being able to react. You want to focus your strongest tricks on it immediately. Tokos don't have a ton of HP or high defenses, but they will evade almost every normal attack you throw at them. They can't evade tricks.
Focus only on the Toko or the thing is almost certain to get away from you once its turn comes up. If you're facing two Tokos, use an area-striking or all-hitting attack instead, and consider swapping characters so you can direct everyone towards attacking these beasts.
Killing Tokos requires patience, but not as much as you might think. They're not outrageously rare, and you'll probably come across one with five or ten minutes of dedicated searching. Remember: Veil is your best friend when hunting Tokos! If you don't have this spell, get it!