Delta Airlines in recent inventory update has closed reservation for Tokyo Narita – Guam route, with last flight available to book on 08JAN18. Pending on seasonality, this route is served 10-12 weekly. For mid-January 2018, previous listing shows 11 weekly flights with Boeing 757.
DL608 NRT1010 – 1455GUM 752 D
DL610 NRT2025 – 0115+1GUM 752 x246
DL607 GUM0630 – 0920NRT 752 x357
DL609 GUM1610 – 1910NRT 752 D