A desktop pet that does not need you

The obvious way to build a desktop companion is to make it need something. Feed it, talk to it, keep the streak alive. That pattern works, briefly, and then it turns into a small daily debt you resent.

Mochi is built on the opposite rule: the pet has no negative emotions directed at you. It does not get sad when you ignore it. There is no streak, no level, no badge, and no notification that says it misses you. When nothing is happening it sleeps, which saves battery and is also the honest thing for it to be doing.

Why that is a design constraint and not a slogan

Once you decide the pet cannot guilt you, several easy features become unavailable, and the work moves elsewhere.

You cannot use engagement to signal that the product is working, so the product has to visibly work. The pet reacts to the hotkey inside 100 ms, before anything else happens, because that reaction is the whole emotional contract. A note has to be in your vault seconds after you stop talking.

You cannot use a loading spinner as a personality. A pet stuck in the thinking state is a bug, not a state, so every path out of thinking is defined.

You cannot decorate. There is one exclamation mark in the entire product, at the moment the pet hatches, and none anywhere else. The cuteness has to live in the proportions and the motion instead of in the words, because the words have to survive being read over a screen share in a work meeting.

The part that makes it stick

The pet looks like you. You upload one photo, it becomes a caricature with an oversized head and stubby arms, and then that specific character sits at the edge of your screen taking your notes. Nobody else has yours.

That is also the part with the sharpest legal edges, so the rules are strict: the photo is processed once and deleted, no face template is ever created, no recognition is performed, and there is a full path to a ready-made pet so nobody has to upload a face at all.

A companion you would notice the absence of, that never asks for anything. That is the whole design.