Marsel Bait
Marsel Bait

I'm Marsel,
a product designer in Tokyo.

I design products for two kinds of users: Humans + AI Agents.

see my work ↓
resume ↗ linkedin ↗ npm ↗

Selected work

Enjin.world Web platform redesign

Redesigning a career platform for bilingual students and professionals

Sole designer on the 2023 revamp, within nearly four years on the product. Three services, three sub-brands, one system. Mobile-first responsive web; this case study follows the mobile experience.

See the redesign
Enjin mobile login screen, navigate your future, held in hand
Nankai Trough Check Website + MCP server

A bilingual hazard map on cited government data

A free website: search any address in Japan and see the official projected earthquake shaking and tsunami height, in English or Japanese. The same data also runs as an MCP server, so AI assistants can answer with it.

See how it works
Nankai Trough seismic intensity map of Japan, color graded by shaking strength
manabiAI Landing site + visual design

A current, credible face for a course in AI and n8n

Landing site for a course in AI and n8n workflow automation. Visual design, layout, and system for a young, AI-fluent audience.

See the site
manabiAI landing page shown in a floating browser frame on a dark backdrop
Miraidukuri Tour website + brand & print

Design for a Tokyo social enterprise

Tokyo social enterprise spanning tourism, regional revitalization, health, and the circular economy. Design across tour booking, brand identity, and print.

See the work
Miraidukuri site hero, timeless wisdom future vision, over a Japanese kaiseki table

Tools for AI agents

My view is that AI agents are becoming a real part of how customers interact with products. I have spent my career designing for people, and I think this next chapter asks us to design for agents as well. That is what MCP servers are to me: interfaces agents call directly, built with the same care as any UI. Eight shipped on npm, over 20,000 downloads to date.

MCP · npm Rippr YouTube transcript extractor for AI agents. MCP server and Chrome extension, no API keys. MCP · npm Japan UX MCP A Japanese UI correctness enforcer. Audits CSS and markup against the JLReq and JIS standards. MCP · npm PayPay MCP MCP server for PayPay, Japan's largest QR wallet. Built on the Open Payment API.

Also: Nankai Trough Check, Rakuten, Xendit, tabedata, pdf-it. More on GitHub and npm.