I think I'm missing one half-marathon, but otherwise I'm pretty sure this is everything Yuki Kawauchi ran this year. 17 wins in 34 races.
Mari Tanigawa Half-Marathon, Tokyo, 1/8/12 - 1:06:19 - 2nd
Okumusashi Ekiden 6th Stage, 9.283 km, Hanno, 1/29/12 - 27:15 - 1st
Kagawa Marugame International Half-Marathon, Kagawa, 2/5/12 - 1:02:18 - 27th - PB
Tokyo Marathon, Tokyo, 2/26/12 - 2:12:51 - 14th
Saitama Half-Marathon, Saitama, 3/12/12 - 1:04:26 - 1st
Satte Sakura 10-Mile Road Race, Satte, 4/1/12 - 48:07 - 2nd
Yaizu Minato Half-Marathon, Yaizu, 4/8/12 - 1:03:48 - 2nd
Kasumigaura Marathon, Tsuchiura, 4/15/12 - 2:22:38 - 1st
Dusseldorf Marathon, Dusseldorf, 4/29/12 - 2:12:58 - 8th
Nittai University Time Trials 5000 m Heat 18, Yokohama, 5/6/12 - 14:00.02 - 4th
Sendai International Half-Marathon, Sendai, 5/13/12 - 1:03:49 - 4th
Gifu Seiryu Half-Marathon, Gifu, 5/20/12 - 1:04:13 - 12th
Kurobe Meisui Half-Marathon, Kurobe, 5/27/12 - 1:05:38 - 2nd
Sakuranbo Half-Marathon, Higashine, 6/10/12 - 1:05:34 - 1st
Okinoshima 50 km Ultra, Okinoshima, 6/17/12 - 2:51:45 - 1st - CR
Gold Coast Marathon, Brisbane, 7/1/12 - 2:13:26 - 4th
Hokuren Distance Challenge Abashiri Meet 5000 m, Abashiri, 7/7/12 - 14:09.37 - 25th
Shibestu Half-Marathon, Shibetsu, 7/22/12 - 1:05:00 - 1st
Kushiro Shitsugen 30 km Road Race, Kushiro, 7/29/12 - 1:35:02 - 1st
Nihonkai Melon Half-Marathon, Oga, 8/5/12 - 1:06:15 - 1st
Hokkaido Marathon, Sapporo, 8/26/12 - 2:18:38 - 1st
Harunako Ekiden 4th Stage, 5.5 km, Harunako, 9/2/12 - 15:48 - 1st - CR
Sydney Marathon, Sydney, 9/16/12 - 2:11:52 - 1st - CR
Nittai University Time Trials 1500 m Heat 12, Yokohama, 9/22/12 - 3:50.51 - 1st - PB
Nittai University Time Trials 5000 m Heat 37, Yokohama, 9/23/12 - 13:58.62 - 7th - PB
World Half-Marathon Championships, Kavarna, 10/6/12 - 1:04:04 - 21st
Chiba Aqualine Marathon, Chiba, 10/21/12 - 2:17:48 - 1st
Joshu Ota Subaru Half-Marathon, Ota, 10/28/12 - 1:05:55 - 1st
Hasuda 3 km Road Race, Hasuda, 11/3/12 - 8:44 - 1st
Oshu Maezawa 30 km Road Race, Oshu, 11/4/12 - 1:33:12 - 1st
Ageo City Half-Marathon, Ageo, 11/18/12 - 1:03:02 - 3rd
Fukuoka International Marathon, Fukuoka, 12/2/12 - 2:10:29 - 6th
JBMA Jingu Gaien 10 km Road Race, Tokyo, 12/9/12 - 38:04 - guest appearance
Hofu Yomiuri Marathon, Hofu, 12/16/12 - 2:10:46 - 1st