The race saw Seo, who secured a fifth-place finish in the 400 IM in 4:26.05, come out in second place after the butterfly and backstroke before falling into sixth place following the breaststroke. He salvaged fourth place with a 29.35 freestyle split.
Kropp, who competed as a member of Rattler Swim Club, began the meet with a bang on Monday, winning a championship in the 200 breaststroke in a meet-record 2:28.70.
"It definitely was a really great feeling," Kropp said of her win in the 200 breaststroke that came on the heels of a fifth-place finish in the same event in the 2010 ConocoPhilips National Championships on Saturday at the same venue. "Coming off Nationals, I felt like, 'Here's Junior Nationals, I have to win this to cement my standing.'"
Kropp was then able to qualify for the consolation final of the 100 breaststroke on Thursday, where she finished fourth (12th overall) in 1:11.91, but she fell well short of the finals in the 200 IM on Friday with the 41st-best swim in the preliminary heats in 2:21.81.
"I was a little disappointed [with the 200 IM], but I'm increasing my yardage and working up to a higher aerobic level to focus on [the Junior Pan-Pacific Championships] in Maui," Kropp said. "I was fine with [the result] because I know it will pay off in Maui."
Kropp, who won her second career CIF title in the 100 breaststroke in May, received a disqualification in the 400 IM on Tuesday. Next up for Kropp are the Junior Pan-Pac Games, which begin Aug. 26 and run through Aug. 30.
"I'm glad I got the opportunity to practice all my best swims," Kropp said. "I didn't get my best times, but I'm happy with my swims."
Seo, who led the Falcons to a runner-up finish in CIF this season, finished 58th overall in the 100 breaststroke in 1:07.20 on Thursday.