On Sep 9, 井口邦 and related parties submitted the Large Shareholding Report to Ministry of Finance to disclose its 6.28% ownership of the shares in $Tripleize (5026.JP)$.
Source: Edinet Announcement
What is the 5% shareholding reporting system?
Shareholders with holding ratio exceeding 5% must submit a Large Shareholding Report within five business days from that day. If the holding ratio increases or decreases by 1% or more after submitting a Large Shareholding Report, the holder must submit a Change Report within five business days from that day.