Nobori is one of the leaders of the Battle Subway in Pokemon Black and White, along with Kudari.
Nobori made his debut appearance at the end of BW045 along with Kudari where they detected Team Rocket's tampering with the track switches. In BW046 the pair went in search of what or who was causing these disturbances and they caught a glimpse of two figures before they disappeared into the shadows.
In BW047 and BW048, Nobori and his brother met Ash, Cilan, and Iris as the subway they were riding had stopped.
Nobori and his brother reappeared in BW051, where they had a tag battle against Ash and Cilan, who were using Tepig and Pansage respectively.
Nobori is referred to as "big brother" by Kudari indicating that he's the older of the twins.