User blog comment:Kaido King of the Beasts/Three Things You Never Forget: 9.11, Harambe, and the Debt I Owe You/@comment-27930128-20160916134034/@comment-3203286-20160916135001

It's a tribute to Kochikame, the longest running Jump series that just ended with 200 volumes. Several other Jump series paid tribute to it this week as well.