The 28-year-old hairdresser and city councilor is among a small but growing number of Japanese women entering the male-dominated world of hunting, where it was once taboo for men to even speak to a woman before going on a hunt.
As the hunting fraternity shrinks due to age and rural depopulation, women are recruited to help protect farms against rising numbers of wild deer and boar viewed as pests by farmers.
Farmer Manabu Ushiyachi said he welcomed any hunter, male or female, to help fend off the wild boar that feast on vegetable crops.
"There are farms that have been completely devastated," he said, adding that attempts to trap the animals had failed.
Japanese farmers have lost up to 23 billion yen ($170 million) annually since 2008 because of rising numbers of deer, boar, monkeys and birds, the Ministry of Agriculture said last month.
"We've tried methods such as building fences or chasing animals away to minimize their deaths, but it wasn't enough," said Kazuhiro Akiba, head of the ministry's Wildlife Management Office in Fukui.
Since the late 1990s, the number of deer in Japan has jumped from less than 400,000 to more than 3 million, according to the Ministry of Environment. The boar population doubled to 1 million over the same period.
Akiba said hunting was necessary to "keep the numbers under control to maintain a healthy ecosystem."
Of Japan's 105,000 registered hunters, two-thirds are 60 or older, and only 1,169 are female, according to the National Hunting Association, which counted 500,000 hunters in the 1970s.
Hunting groups and local governments are trying to recruit women through social media, as well as offering hunting tours and classroom training.
The national association's website has a blog page titled "Aspire to be a Female Hunter!", where women write about their hunting experiences. One writer noted the "kind gesture" when she found portable toilets for female hunters in rest huts.
In some prefectures, women can sign up for hunting courses or join a hunting tour. Others, like Kodama, provide on-the-hunt training.
After shooting the deer, Kodama and her 28-year-old friend, Aoi Fukuno, followed the blood trail and found the dead animal lying on a fallen tree. Kodama then showed Aoi how to gut the deer and lay it in a river to drain the blood.
"It's exciting to finally see with my own eyes what I read in textbooks to get my license," said Aoi.