Nagashima Ohno & Tsunematsu, one of the four largest Japanese law firms, has formed an alliance with a legal technology company – a rare move for a major firm in Japan.

Nagashima Ohno formed an alliance with MNTSQ Ltd., an 11-month-old Tokyo-based legaltech startup and an affiliate of Tokyo-listed machine-learning technology company PKSHA Technology Inc. As part of the agreement, Nagashima Ohno will invest about $7 million in MNTSQ during the next several years. And MNTSQ will help the firm conduct due diligence using its natural language processing technology.