Kochi was formerly known as Tosa (土佐).
The Yoshino river about an hour North of Kochi city offers Japan`s best white-water rafting. This is a very rural part of Kochi surrounded by steep forrested mountains.
Pint-sized Kōchi Ryōma Airport (IATA: KCZ)  has flights to Osaka-Itami, Osaka-Kansai, Tokyo-Haneda, Nagoya-Komaki and Naha (Okinawa). Buses to/from Kochi station (35-45 min, ¥700) leaves roughly twice an hour.
The most popular way to arrive in Kochi by train is from Okayama, which is on the main island of Honshu. From Okayama take the Limited Express Nanpu train, and you will arrive in Kochi in approximately 2.5 hours.
The local specialty is katsuo no tataki, bonito quickly seared under high heat so the surface is cooked while the inside is still raw.
Liquor in all forms: the people of Kochi are known as the biggest drinkers in Japan. The women in Kochi are particularly renowned for their affinity and ability to drink. They are refered to as Hachikin, literally meaning 8 testicles since it is said that one Tosa (Kochi) woman can drink like four ordinary men. Kochi offers an abundance of locally made sake and shochu, and the friendly locals will surely approach you for a fun interaction at Kochi`s numerous bars.
17 sake breweries in Kochi make Tosa Space Sake (土佐宇宙酒 Tosa uchūshu), prepared with yeast that was taken into space for ten days and back aboard a Soyuz rocket in 2005, so be sure to sample some for a taste experience that is out of this world. Alternatively, try to track down some space yoghurt (宇宙を旅したヨーグルト Uchū wo tabi shita yōguruto, lit. "The yogurt that travelled in space") , prepared from the same yeast.