Shimada was born in Ōmura, Nagasaki Prefecture, Japan, on 7 July 1898, into a family of farmers. At some point she got married, and went on to have five children. Her husband passed away before she was 40, and she raised four of their children on her own while working as an insurance saleswoman. As of July 2009, she had six grandchildren and twelve great-grandchildren.

At the age of 103, she suffered a serious bout of pneumonia. Despite doctors informing her family that she had only three days left to live, she made a near-complete recovery. After her recovery, she moved into hospital permanently to receive long-term treatment. Some news reports stated that Shimada seemingly possessed an extraordinary ability to recover from illness. Not only did she defy the odds when declared to have terminal pneumonia, but when her condition took a turn for the worst on another occasion in October 2007, she once again made a full recovery, and by February 2008 and was said to be doing well again. Her health deteriorated again in August 2009 due to fatigue from the summer heat, but once more, by the next month, she recovered.

In July 2006, a birthday party event was held for Shimada at a hotel in Isahaya City. The event was attended by the city mayor and around seventy of her relatives. Her son Hiroshi, speaking at the time, said, “My mother’s sole reason for living after enduring the poverty and suffering of the war period was working hard to ensure the prosperity of her children.” In spite of being wheelchair bound and slightly hard of hearing, she was said to be in excellent health at the time. In September 2006, Shimada joined her local Centurion Lions Club, an international humanitarian organization active in over 200 countries. A welcome ceremony was organized at the hospital where she resided. She was oldest member of the club in Japan. She was a valued member of the club, and several celebratory events—some boasting hundreds of attendees—were held at the hospital between 2006 and 2010.

In February 2008, when Shimada was 108 years old, a special event to celebrate her longevity was held at a hotel in Isahaya City. There were around a hundred people in attendance including the city mayor, Shimada’s relatives, and seven of her great-grandchildren. The mayor presented her with a congratulatory bouquet of flowers, and a meal featuring her favorites, chawanmushi (savory steamed egg custard with chicken, mushrooms, etc.) and sashimi, was served. She surprised those present with her hearty appetite, finishing her meal completely unassisted. Besides chawanmushi and sashimi, Shimada also enjoyed eating eel. Her hobbies were traditional Japanese dance, and the shamisen and biwa, traditional Japanese stringed instruments. In July 2010, Shimada was visited by the prefectural governor in her hospital ward to celebrate her 112th birthday.

Shika Shimada passed away at a hospital in Isahaya City, Nagasaki Prefecture, Japan, on 20 July 2010, at the age of 112 years, 13 days.