Fowler shot 65 and moved to T-7th, while Schauffele, who turned 31 as he played the second round carded 65 and moved up to T-42 and Morikawa scored 67 to be T-22.
Indian-American Sahith Theegala, who shot 72 on Day 1, improved to 68 and is now T-52nd. Kevin Yu of Chinese Taipei, who won recently on PGA Tour, with 65-68 is T-8th.
However, the lead was held by Colombian Nico Echavarria, who shot a 6-under 64 on Friday, to match his 64 on Thursday to lead by two shots over Taylor Moore and Justin Thomas after the second round. Thomas shot 64 and Moore carded 67 with three others just three shots off the lead including Seamus Power, who had the day's low round of 62 at Accordia Golf.
Thomas has twice won the PGA Championship but is winless in two years on the PGA Tour. Eric Cole (67) and C.T. Pan (66) were also three behind heading to Saturday.
Echavarria, whose lone PGA Tour win was in Puerto Rico, had a two-round total of 12-under 128.
Fowler, a crowd favourite in Japan, shot 64 to go with an opening 68 and was four shots back going into the weekend. Max Greyserman was also four behind after a 68.
“It would be amazing to win here,” said Fowler, whose mother has Japanese roots. “Came close a few years ago.” Fowler tied for second in 2022.
Japanese star Hideki Matsuyama shot his second 71 and was 14 shots off the lead. Morikawa shot 67 and pulled within eight shot of the lead, and Schauffele — The Open and PGA Championship winner this season — shot 65 and was 10 behind after a 73 on Thursday.
Schauffele, whose mother grew up in Japan and his grandparents live in the Tokyo, turned 31 on Friday, and he was serenaded before his opening tee shot.