Unlike in previous entries, Shin Megami Tensei V’s shop system revolves around a single merchant: Gustave, a demon that collects shiny things. While Gustave doesn’t travel around in the strictest sense, they will be available as a permanent merchant upon unlocking them.
You must unlock Gustave’s shop — the Cadaver’s Hollow — as part of the tutorial. After landing in the Netherworld and dispatching your first few enemies, you will notice a column of light. These Leylines serve as access points to a variety of services — the Cadaver’s Hollow being the first you unlock. Upon unlocking Cadaver’s Hollow, all future Leylines will have an option to access it, so don’t worry if you’re strapped for Macca — Gustave isn’t going anywhere.
The shop features a variety of items, ranging from healing items such as Medicines and Amrita Sodas, to offensive items, such as Elemental Shards, which allow you to deal Elemental Damage of varying types. Gustave will also, later on in the game, sell Essences of Demons, which will allow you to fuse skills and affinities to your roster.
You can also sell your junk items for Macca here, and access the Mimin Hunt mini-game as well, which sends you on a hunt around the world looking for Gustave’s minions. Every five you find, Gustave will give you a reward, so keep your eyes peeled.