The Scheme Team

Episode AG132 - "Brock's hand is right over Ash's when the group splits into two, and lingers a fraction of a second longer than May and Max's do, despite him not leaving Ash just yet." (Bulbapedia, 2012)

You can watch it here, the scene is about 2:40
http://www.mojvideo.com/video-pokemon-409-the-scheme-team/f2a9b1cdf4fed5dd50d1

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A similar case: Memories are Made of Bliss!
"Near the end of the episode [DP191], before Ash and Brock part ways, they hold hands for a long period of time. They eventually, and slowly, let each other go." (Bulbapedia, 2012)



More screenshots: http://www.filb.de/anime/dp/191


You can watch this episode here
http://watchpokemonepisodes.com/pokemon-episode-653



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