Eiyuden Chronicle: Hundred Heroes

Basically buy all four levels of the stowbag shop. The shop doesn't physically exist ingame from what I can tell and just building the upgrades from the drafting studio provides the upgrades.

To fully upgrade the stowbag shop:

* Upgrade castle to level 4, requiring 480 food, 60 pelts, 4 excellent lacquer, 2 legendary beast horns, 100 allies and 56560 funds
* Recruit Nell (find them in Hishahn, hiding behind some stalls near the northwestern entrance) and Code L (he's in the Daphan Village rune shop and requests to be shown a Rune of Currents)
* Build or buy the following buildings/upgrades: Trading House, Trading House renovation, Rune Shop, Stowpack Shop, Stowpack Capacity 1, 2 and 3. This requires 100 lumber, 1130 pelts, 6 ancient dragon teeth (only available via Mission Guild task Beast Busters) and 12,900 funds

To max out the Mission Guild for the task/teeth:

* Upgrade castle to level 4 (see requirements above)
* Recruit Martha, Huang, Kurtz and Clarke (Caine and Goteau are also required but are automatically recruited)
** Martha can be found in the eastern side of the fortress town
** Huang is in Hishahn near the appraisal shop (may require defending Hishahn before he'll appear) then catch a wheel-eyed bream, which can be found in Seaside Cavern or just southwest of Seaside Cavern, lucky charm on Nowa recommended
** Kurtz is also in Hishahn, and requires the grilled tutuva recipe from the Treefolk Village. The NPC with the recipe only spawns after talking to Kurtz
** Clarke is in Ardinale City. Visit the city as Nowa, talk to him then buy the Star-Cross'd Lovers script from the city's tool shop. It's a rare spawn that has a chance to appear every 10 minutes apparently
* Build or buy the following buildings/upgrades: Pasturage, Fishing Spot, Fishing Spot Product 1, Mission Guild, Mission Party 1, Mission Task 1, Theater, Mission Task 2, Mission Party 2, Mission Task 3, Mission Task 4 (costing 20 lumber, 2 mystic lumber, 1 iron ore, 130 pelts, 3640 food, 1 dire beastbone, 3 legendary beast horns, 3 sacred tree chips and 64860 funds)
* Send out a party on the task "Beast Busters", return to the guild in 90 minutes and collect the six ancient dragon teeth (each task takes half an hour and worst case scenario awards two teeth for an epic failure, but successful missions grant three teeth)

As the maximum storage allowed for basic resources (lumber, stone, food and pelts) is 2000, it won't be possible (or advisable) to max out the guild in 1 sitting