tonari_no_seki-kun_junior
A 2020 slice-of-life comedy manga spin-off of Tonari no Seki-kun by artist Morishige Takuma (morisiget). In it Yokoi Rumi has grown up and had a child (Makuru (Tonari no Seki-kun Junior), whose father is implied to likely be Seki Toshinari). She interacts with her sons' antics in a very similar way to how she did with Seki in the original story.