Makino was running inside the top 10 on the opening lap when Red Bull junior Liam Lawson suffered a spin while battling with Mugen team-mate Tomoki Nojiri for the lead.
The Dandelion driver was unable to avoid the out-of-control Mugen car ahead of him, with the contact sending his car airborne.
Makino landed on track in a near-upright position before smashing into the armco barriers adjacent to a marshal post on the other side of the track, suffering another significant hit.
It's understood that Makino needed assistance to exit the cockpit of his stricken Dandelion car, and that he was subsequently airlifted to hospital via helicopter for further checks.
The 26-year-old is understood to have reported back and chest pain after the incident.
A Dandelion team representative told Motorsport.com's Japanese edition that Makino avoided any major injuries, and the 26-year-old posted on social media that he had left hospital on Monday.
昨日のクラッシュで沢山の方にご心配をおかけしました。
— Tadasuke Makino・牧野任祐 (@tadasuke0628) August 21, 2023
クラッシュ後のオフィシャルさんやメディカルチームの方々、搬送された病院で検査して頂いた医師の方々のおかげで一晩入院していましたが退院できました。
少し安静にしてまた次に向けて準備していきます！
大変ご心配をおかけしました。 pic.twitter.com/rcwIKJl0ng
Makino's post made no specific mention of this weekend’s SUPER GT race at Suzuka, where he is due to drive a Team Kunimitsu Honda NSX-GT alongside Naoki Yamamoto.
Apart from Lawson and Makino, B-Max driver Nobuharu Matsushita and Impul’s Yuhi Sekiguchi were also involved in the melee, which caused the race to be red-flagged.
Matsushita, Sekiguchi and Lawson all escaped the incident without any injuries, with Lawson even able to take the restart after getting his car repaired under the red flag.
The race was won by Nojiri, with the result helping him return to title contention ahead of the title-deciding races at Suzuka in October.
Lawson finished over a minute down in 13th place after serving a drive-through penalty for getting his car repaired under the red flag.
