We recommend the following transportation route to the invited overseas visitors.
From the airport to JR Kyoto Station or the hotel
A staffer will be waiting for you at the arrival gate, and help you to get to JR Kyoto Station or directly to the hotel. The detail will be explained by the travel agent by e-mail.
From JR Kyoto Station to the hotel
Take a subway Karasuma Line and get off at Marutamachi Station. There are 4 stops, and it takes about 7 minutes and cost 260 yen. Then, walk for 5 minutes to north along the imperial palace, and you will find the hotel on your left.
From the hotel to Kyoto University
Walk north for 15 minutes to the bus stop Karasuma Imadegawa. Take Kyoto City Bus (not Kyoto Bus) number 203 and get off at Kyodai Nogakubu-mae. There are 5 stops, and it takes about 8 minutes and cost 230 yen. This is a reasonable one, though the follwing map may suggest you some other options.
From the bus stop Kyodai Nogakubu-mae, it takes about 2 minutes to the Department of Mathematics on foot.