Ten-year-old Koharu Yagi gazes at the meters and meters of plastic train track laid out in a room at the Plaza North culture center in the city of Saitama and lets out a sigh of wonder.

"It's like a dream being able to play with something as big as this," he says. "Something I could never make at home."

Welcome to Purafesu, a semi-regular event aimed at fans of toy trains organized by YouTube personality Yoshimasa Matsuoka, which held its most recent edition at Plaza North from Dec. 22 to 24.