Kihira then recorded the best score in the free skate, despite a fall, to easily beat fellow 16-year-old Alina Zagitova, this year's Pyeongchang Olympics champion.
"My first Axel I had a mistake but I was able after that to regroup and finish my performance with no more mistakes," Kihira said via an interpreter.
"I was able to change from a state of nervousness into concentration."
Kihira posted a total score of 233.12 for her third grand prix victory of the season.
Russian Zagitova, last year's grand prix champion, finished second on 226.53 points.
Compatriot Elizaveta Tuktamysheva was a distant third on 215.32 points.
Despite her youth, Kihira said that she had learned from past mistakes.
"Last season and the season before that I had many failures. And I promised myself I would remember them and never repeat those mistakes again.
"Although I did have one mistake (today), at this point I'm really satisfied with myself."
Kihira's long-term goal is to win gold at the 2022 Beijing Olympics.
"Ever since I was a child I've dreamed of going to the Olympics," she said. "I have this dream of going to the Beijing Olympics and winning there."
Chen tops Uno to take men's gold
Nathan Chen in the Free Skate portion of the Men's Competition at the ISU Grand Prix of Figure Skating Final in Vancouver, British Columbia, Canada. Source: Getty
American Nathan Chen finished with a total of 282.42 points, comfortably ahead of Japan's Shoma Uno's 275.10, with 17-year-old Junhwan Cha of South Korea finishing third with 263.49 points.
"It's a huge honour to be at the final with these two guys," said Chen. "They have brought a lot to skating and I'm glad to be able to share the ice with them. There are a lot of things I can work on and improve."
Chen came into Friday's free skate with a slim lead over Uno after Thursday's short programme, where the favourites both made mistakes.
Skating to "Land of All" by Woodkid, Chen nailed his opening quadruple flip before failing to land the following quadruple Lutz.
But the 19-year-old reigning world champion more than made up for his mishap as the programme wore on, gaining confidence throughout his routine to seal a decisive victory before a supportive crowd in Western Canada.
