Yes, Shukichi is basically saying that he and Yumi were doing “it” the whole night last time she stayed over at his place. While proofreading this chapter, it led me to write this little joke dialogue:
Shukichi: “After all, you didn’t get any sleep because I was checkmating you with my gold general the whole night…” Yumi: “…”
And now I can’t stop the headcanon that Shukichi is using terribly forced Shogi metaphors and allusions for dirty talk, annoying Yumi to all hell XD
Also: it paints this scene from File 1013 in a whole new light:
Yeah, Yumi, it sounds you did a lot of … “convincing” :D
