Tzuyu is the most unwise girl to expose those guys who attempted to date her ot have dated her. She just couldn't keep it to herslef with or without her own device. She is either too naive or caclulating by dating the guys from same group or same pool!!! Either way, it only shows she is a ignorant girl.
On that ISAC tournament? I doubt very much that Tzuyu was anywhere close interested in that young fella, standing a few feet from her right. She did do quick glance at something? At 1:10 to 1:14? Look very closely at her eyes in those few seconds. She do a quick glance? But at the two or three others persons! That were standing in front and to her right side "view of sight" and she didn't even smile or grin. That's my opinion.