On Sep 17, 白井 基治 and related parties submitted the Change Report to Ministry of Finance. The report shows that 白井 基治 and related parties increased their holdings in $Shirai Electronics Industrial (6658.JP)$, with their joint shareholding ratio up from 5.04% to 6.1%.
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.