I don't think I mentioned this. In Super Smartphone, Moura's Googugu screen is in pictographs and onomatopoeia on part of him being slow-witted.
A closed fist "gu" + elongation squiggle ~ = "guu"
ぐ "gu" ＋ Gu (グッ) the SFX for a thumbs up/グッドサイン (good sign.)
