|“||Those who think they'll win are full of openings.||”|
Midorikawa is a short boy with messy chin-length brown hair and green eyes.
He has two uniforms. The first one, first seen during the Border Enlistment Arc, is an all-white Border uniform, similar to the C-rank uniform but with black stripes instead of orange ones. His uniform also has horizontal stripes on the collar and around the tips of his jacket's sleeves, and vertical black stripes on the front sides of his pants. He always wears his jacket unfastened, possibly as a nod to Jin, who wears his jacket in the same fashion. He also wears goggles around his neck, another possible reference to Jin. He also wears dark blue boots with white vertical stripes and gray soles. He wears this uniform again in the B-Rank Wars Arc.
His second uniform, and his Squad's uniform, first seen in the Large-Scale Invasion Arc, consists of a black jacket with sleeves that reaches to his elbows with the upper halves being golden and striped. It has white stripes on the borders of the collar, zip fastener and bottom, and also from the collar until the sleeves and also golden stripes around the edges of the sleeves. On his left chest is the Kusakabe Squad emblem, and beneath it, the jacket has an interior pocket on each side, both with golden covers and silver buttons. Along with it, he wears black pants and gold-colored boots.
Yoneya has likened Midorikawa's personality to a "puppy dying to show off its talents". This was shown when he humiliated Osamu by defeating him effortlessly ten times in front of a large crowd, and when he became increasingly angry being defeated by Yūma time after time until finally recognizing Yūma's strength and calming down, although he was still defeated. However, in front of Jin, he acted very silly and energetic, because Jin saved Midorikawa in the past. He looks up to Jin and wants to join Tamakoma Branch. He has been shown to be able to think logically and strategically in a battle.
- (To Lamvanein) "Those who think they'll win are full of openings." 
- (About Tetsuji Arafune) "Arafune was an attacker until 8 months ago. Besides, he had a good ranking. He still participates in rank battles with his Kogetsu. When he stopped being an attacker, everyone wondered why." 
- Shun (駿?) means "spirited horse". Midorikawa (緑川?) literally means "green river".
- Coincidentally, he has green eyes.
- His English voice actor, Nick Wolfhard, also voices Miyoshi.
- He has the habit of nicknaming others.
- He likes grilled meat, winning in rank wars, and Jin.
- World Trigger Manga — Chapter 59 (p. 18)
- World Trigger Manga — Chapter 58 (p. 19)
- World Trigger Manga — Chapter 40 (p. 2)
- World Trigger Manga — Chapter 93 (p. 4)
- World Trigger Manga — Chapter 40 (p. 12)
- World Trigger Manga — Chapter 39 (p. 12-16)
- World Trigger Manga — Chapter 41 (p. 9-18)
- World Trigger Manga — Chapter 41 (p. 2-3)
- World Trigger Manga — Chapter 90 (p. 3)
- World Trigger Manga — Border Briefing File (p. 58)