Using HYPERDIA

Hi!

I was trying to check Hyperdia for this route: from Shin-Koiwa Station to Echigo-Yuzawa Station. The route was from Shin-Koiwa to Tokyo to Echigo-Yuzawa Station without transfer. I checked the schedule for 7AM and the earliest schedule is at 7:16AM. I tried checking if there was a schedule around 6:30AM, but there was none.

But when I tried checking it separately, Shin-Koiwa to Tokyo Station and Tokyo to Echigo-Yuzawa Station, surprisingly there is a 6:38AM schedule for Shin-Koiwa to Tokyo Station, and 7AM schedule for Tokyo to Echigo-Yuzawa Station, separately.

My question is, how come there is no 6:38AM schedule when I was trying to check for Shin-Koiwa to Echigo-Yuzawa directly? But when I tried searching for the route separately, they have a schedule earlier than 7AM.

Thank You and Best Regards,
Jorelle