15th Rock is a Tokyo-based venture capital firm focused on Human Augmentation (primarily hardware) and Consumer 3.0 (primarily software), investing from seed to pre-IPO stages across Japan and the United States.
Average disclosed round size is $6.8M (across 4 rounds with reported amounts).
Portfolio
6
Fund Size
—
Top Stage
Seed
Last 12 Mo
1
Team
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
8 investments
| Company | Round | Amount | Date |
|---|---|---|---|
 LetzRyd | Seed | $4M | Jan 2026 |
| BBisu | Seed | $3.2M | Oct 2021 |
 Onera | Series C | — | — |
| Onera | Series B | — | — |
 Cellid | Unknown | $13M | — |
 Onera Technologies B.V. | Series C | — | — |
| Onera Technologies B.V. | Series B | — | — |
| PProton Intelligence | Seed | $7.0M | — |
Top Co-Investors
imec.xpand4 shared
Invest-NL4 shared
Innovation Industries4 shared
EQT Life Sciences2 shared
Gimv2 shared
SOSV2 shared
Development Bank of Japan Inc.1 shared
Global Brain Corporation1 shared
India Quotient1 shared
JIF Capital1 shared
HAX1 shared
QUAD1 shared
We Venture Capital1 shared
Exor Ventures1 shared
Tenmile1 shared
LongeVC1 shared
Last updated: 8 September 2026