He has sandy blonde hair that may have been dyed, judging from his dark sideburns and eyebrows. He has a large muscular build and is often seen scowling or yelling at someone (particularly, Futakuchi Kenji).
He is loud and strict and takes the game seriously. He often argues with and threatens Futakuchi Kenji, a problematic junior who doesn't show much respect for his seniors. He is quite competitive and belligerent: when he saw Karasuno at the Spring High, he gave them the middle finger and made a face without holding back at all.
Kamasaki took part in the game between Date Tech and Karasuno. During the game, he and Futakuchi would at times argue and have to be kept apart by Aone at Moniwa's request. After Date Tech lost, Kamasaki and the other third years retired from the team.
Spring High Preliminary ArcEdit
Along with Moniwa and Sasaya, Kamasaki attended the last half of Date Tech's game against Aobajohsai. He finds himself amused at the fact that Futakuchi, who has become the new team captain, is having trouble handling the new team setter Koganegawa. Kamasaki is shown being incredibly supportive for the remainder of the game. Afterwards, he would give advice to the team of how they could continue to grow stronger and he would also agree to help with practices.
Tokyo Nationals ArcEdit
Kamasaki, Moniwa, and Sasaya would sneak into Date Tech's gym (Karasuno in the anime) to watch the practice match between Date Tech and Karasuno. He is mostly seen cheering for the team from the balcony area. After the match, he would wish the Karasuno third years good luck at Nationals and offhandedly mention how he might grow facial hair, possibly from thinking that Asahi came off as intimidating due to having facial hair.
In the coverage of events after Nationals, Kamasaki is with Moniwa and Sasaya in the audience when Date Tech wins the Interhigh tournament. As of 2021, Kamasaki works as an upholsterer in Miyagi.
Along with Aone and Kenji, it's shown that Yasushi has pretty good blocking skills. All three make up the Iron Wall of Dateko.
Jumping Reach: 330 cm
- Favorite Food: White bean paste monaka
- Current Concern: How many "packs" of abs is it possible to have?!
- His star sign is Scorpio.
- He is the series' biggest eater. 
- In Haikyuu's first popularity poll, Kamasaki placed 33rd with 338 votes. In the second, he rose to 29th with 1,420 votes.
- Yasushi (靖志) - Will
- Kamasaki (鎌先) - Sickle