Private today. Open source ahead.
Hikari is currently closed-source software for internal use at Flying Rat Studio. We have committed to open-sourcing it in the future.
- Today
- Proprietary · Internal use
- Our commitment
- A future open-source release
What applies today.
Hikari and its associated documentation are proprietary to Flying Rat Studio. Use is restricted to the studio and authorised personnel, contractors, and agents working on its behalf, under the applicable agreements.
This website showcases the engine; it does not grant permission to use, copy, modify, or redistribute it. Third-party use requires express written authorisation from Flying Rat Studio.
Our open-source commitment.
We have promised to open-source Hikari. The current licence records our intention to release the engine, or portions of it, under the MIT License when the technology reaches a suitable level of maturity.
The timing and scope remain to be determined. Until we publish a new licence grant, the engine remains proprietary and this commitment does not grant MIT or other open-source rights.
The work shown here.
Some screenshots feature scenes and models created by other artists. Their credits and licence information appear alongside the images and in the image viewer.
Those assets remain subject to their own terms. Their licences are separate from the engine licence and do not grant rights to Hikari itself.
Read the current engine licence
The explanation above summarises the current status. The original English licence notice is reproduced below.
PROPRIETARY SOFTWARE LICENSE
Copyright (c) 2026 Flying Rat Studio. All rights reserved.
NOTICE: This software and associated documentation files (the "Software") are
proprietary and confidential to Flying Rat Studio (the "Company"). The Software
is provided solely for the Company's internal use and for use by authorized
personnel, contractors, and agents acting on the Company's behalf, subject to
applicable confidentiality and employment or engagement agreements.
No license is granted hereby to any third party. Except as expressly authorized
in writing by the Company, you may not use, copy, modify, merge, publish,
distribute, sublicense, sell, lease, transfer, publicly display, publicly
perform, or otherwise exploit the Software, in whole or in part, nor reverse
engineer, decompile, or disassemble the Software except to the extent such
restriction is prohibited by applicable law.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND NONINFRINGEMENT. IN NO EVENT SHALL
THE COMPANY OR ITS LICENSORS BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT, OR OTHERWISE, ARISING FROM,
OUT OF, OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
FUTURE LICENSING INTENT: The Company presently intends, at a time of its sole
discretion and upon determination that the technology has reached a suitable
level of maturity, to relicense or publicly distribute the Software (or
portions thereof) under the MIT License. Until such time as the Company
publishes a superseding license grant in writing, this proprietary notice
remains in full force and effect, and no rights under the MIT License or any
other open-source license are conferred by this statement of intent.