A collection of cancelled manga gems—which one is the biggest pity?

Every time I think about works cancelled by JUMP, my heart aches. Some had so much potential but were axed just because they weren't popular enough.<br><br>The ones I find most regrettable:<br>- <i>Ayashimon</i>—Yokai × Yakuza, the premise was super interesting but the pacing was too slow.<br>- <i>Build King</i>—Mitsutoshi Shimabukuro's new work, I was really looking forward to it.<br>- <i>Mission: Yozakura Family</i>—Actually it was okay, but it just lacked popularity.<br><br>Which cancelled series do you find the most regrettable? Are there any hidden gems that you feel would have become great if they had just been given a few more chapters?