Is your final destination located in Kyoto City?
I think there is a chance that the two get combined into a single ticket in this case. I agree.
Maybe your JR basic-fare ticket and your Shinkansen (super-express) ticket are combined, maybe they are separate.
Anyway, I suppose you are highly likely to get issued a JR basic-fare ticket to travel from a station in Tokyo Ward Area [Tokyo tokunai] to a station in Kyoto City Zone [Kyoto shinai], as a single basic-fare ticket / with a Shinkansen ticket combined.
Traveling with this ticket, you are not allowed to make a stopover outside the exit gate(s) at a station in Tokyo Ward Area (e.g. Shinagawa in your case) or at a station in Kyoto City Zone.
In Shibuya Station, you put the single basic-fare ticket / the combined ticket through a gate machine at an entrance gate.
Trains (for Shinagawa) on the Yamanote Line's inner loop depart at Track 2 in Shibuya Station; please note that trains destined to Osaki do not run to Shinagawa.
In Shinagawa Station, you put the both tickets / the combined ticket through a gate machine at either Shinkansen South Transfer Gate or Shinkansen North Transfer Gate.
http://english.jr-central.co.jp/info/station/_img/shinagawa_L.jpgWestbound Shinkansen trains depart at Track 23 or 24 in Shinagawa Station.
In Kyoto Station
http://english.jr-central.co.jp/info/station/_img/kyoto_L.jpg: If you pass through a Shinkansen transfer gate first and an exit gate second,
at the transfer gate the single basic-fare ticket is returned while the Shinkansen ticket is collected / the combined ticket is returned,
and then at the exit gate the single basic-fare ticket / the combined ticket is collected.
: If you pass through a Shinkansen gate other than transfer gates,
that gate works as an exit gate, and a gate machine collects the both tickets / the combined ticket there.