On Oct 28, 伊達 晃洋 and related parties submitted the Change Report to Ministry of Finance. The report shows that 伊達 晃洋 and related parties decreased their holdings in $Birdman (7063.JP)$, with their joint shareholding ratio down from 57.07% to 54.5%.
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.