About Yuichi
I was born in Osaka and raised in Japan before moving to the U.S., where I studied psychology and neuroscience (Highest Honors) at Williams College after time at Keio University. My early experiences — navigating visibility, culture, and identity — became the foundation for how I approach technology today: not just as engineering, but as a system that reshapes how humans feel, behave, and belong.
I’ve worked across healthcare and preventive medicine at companies like M3 and Ubie, conducted memory research at RIKEN, and entered the PhD program at the Max Planck Institute for Brain Research before leaving to build in San Francisco. Now, as co-founder of Taxa Technologies, I lead efforts to engineer the skin microbiome to create new categories in personal care, from long-term deodorant performance to mosquito protection.
I am drawn to frontier problems where technology, society, and market intersect — places where technologies can bend the trajectory of entire industries. My work operates between worlds: Japan and the U.S., science and story, rational design and human emotion. I’m motivated by non-linear leaps, not incremental steps, and by building bridges that let people live with more freedom and dignity.
I’ve been fortunate to serve as a U.S.–Japan Council Associate Leader, a Guest Member of the World Bank Alumni Association Japan Chapter, and an Entrepreneurship Ambassador for Japan’s Ministry of Education. My work has appeared in Nikkei, NewsPicks, Japan News, and SynBioBeta.
If you’re building something that sits at the edge of what’s obvious today — a future category, a cultural shift, a new technological frontier — I’d love to talk. Breakthroughs happen in the spaces in between.
Projects
Taxa Technologies, Co-founder
Co-founded Taxa Technologies, a skin microbiome engineering startup developing long-duration, skin-safe probiotics, beginning with Swap — a next-generation deodorant designed to last for one week after a single application. Backed by top-tier U.S. investors, Taxa operates in both San Francisco and Tokyo, driving microbiome engineering research, clinical validation, product development, and end-to-end commercialization. Our work was featured in Synbiobeta, Nikkei, NewsPicks, and JapanNews.
Context and Contingency in Fear Learning and Extinction
My undergraduate research consisted of two experimental studies using Pavlovian fear conditioning in mice, integrating behavioral paradigms with TRAP2;Ai14 neuronal tagging, DREADD-based chemogenetic manipulation, and automated whole-brain cell-mapping pipelines.
Study 1 investigated how exposure to multiple environmental contexts shapes extinction learning. Using C57BL/6J and 129S1;TRAP2;Ai14 mice, I combined behavioral extinction protocols with chemogenetic activation and inhibition of the dorsal hippocampus via hM3Dq/hM3Di DREADDs and post-training CNO administration. I then tagged extinction-active neurons using the TRAP2;Ai14 inducible Fos-based labeling system. I developed an automated pipeline using ABBA/Allen Brain Atlas registration, QuPath parameter optimization, and machine-learning cell classification to quantify tdTomato+ TRAP-labeled neurons across the brain. This allowed me to examine extinction-related neuronal ensembles and identify MCFE-recruited circuits.
Study 2 conducted a systematic test of the partial reinforcement extinction effect (PREE) by manipulating CS–US contingencies (100%, 50%, 10%), CS duration, trial number, and shock intensity. Across all conditions, mice showed no differences in extinction acquisition, consolidation, or recall, challenging the long-held assumption that partial reinforcement makes fear harder to extinguish.
Together, these studies combined behavioral learning paradigms, chemogenetics, engram tagging, and computational neuroanatomy to refine our understanding of how context and contingency shape the behavioral and neural mechanisms of fear.
Su and Fukunaga et al. (2025). No effect of partial reinforcement on fear extinction learning and memory in C57BL/6J mice. Learning and Memory.
Public Leadership in Entrepreneurship, Technology, and International Development
I serve as an Entrepreneurship Ambassador for Japan’s Ministry of Education (MEXT), where I contribute to national entrepreneurship initiatives and youth innovation policy. I have written on the future of Japanese entrepreneurship in Nikkei, am an Honorary Member of the World Bank Group Alumni Association Japan Chapter, and am an Associate Leader of the U.S.–Japan Council. I also speak regularly on cross-border innovation and biotechnology, including recent talks at Stanford University and UC Berkeley. My work reflects a commitment to bridging entrepreneurship, technology, and international development across Japan and the United States.
Others…
I created a funded online exchange program linking students at Williams College, Keio University, and Nihon University during the pandemic to preserve international collaboration when borders were closed. I also work in visual arts, with photography pieces accepted at UNKNOWN ASIA, and I train as a USA Boxing athlete while enjoying pickleball and living in share houses.
