Photo/Illutration A regular customer makes purchases at the Tenmando confectionery store on Nov. 9 in Kumamoto’s Higashi Ward. A sign at the shop stresses that the sweets are healthier than conventional products. (Yoshiki Yashiro)

KUMAMOTO--A Japanese-style confectionery shop here does more than cater to customers with a sweet tooth. Its other objective is to revive the pleasure of eating something sweet for those suffering from diabetes and other illnesses linked to blood-sugar levels.

The Tenmando confectionery store in this city’s Higashi Ward specializes in non-sugary confections for consumers deprived of eating what they like due to health problems associated with sweet things.

The secret of the store’s popularity lies in crystalline fructose, a type of sweetener that does not result in higher blood glucose values when ingested. Its products are already winning rave reviews despite holdouts among some regular customers.

The store is run by Yumiko Kozuma, 58, who hails from Tamana, Kumamoto Prefecture, and her younger sister, Chikako Higashi, 56.

Their parents ran an outlet that exclusively featured traditional “amazake manju” sweet buns, and Kozuma helped the family business for more than 20 years. Inspired by a friend, the sisters went independent in 2015 to open their own shop.

It features 15 or so items, such as the “ohagi” ball made of rice and adzuki bean paste as well as the “ikinari dango” dumpling featuring sweet potato. They all use crystalline fructose to provide a sweet taste.

The crystalline fructose used at the store derives from corn starch that is not genetically modified. Crystalline fructose does not require insulin secreted from the pancreas for metabolism, thereby keeping blood sugar levels low, the sisters said.

Tenmando used to rely on beet sugar for their products until the pair discovered that the substance can raise blood-sugar levels to some degree.

Kozuma samples all the traditional sweets on sale at Tenmando twice daily for quality assurance and to ensure that all the products are free of artificial additives.

But her blood glucose level rose alarmingly last winter.

That led to the sisters trying to figure out a way to make traditional Japanese-style confectionery without causing high blood-sugar readings. Homemade meals by their mother gave them a clue.

The siblings’ father lived with diabetes for much of his life and was stricken by cerebral stroke in 2014. Concerned about his blood-sugar level, their mother started cooking with crystalline fructose. She has done so for the past 17 years.

Kozuma and Higashi went through a period of trial and error from this past February before developing their new lineup of sweets.

Products using crystalline fructose boast a lighter flavor but have less sweetness and richness than their sugar-based counterparts.

To create a more fragrant aroma, Kozuma and Higashi wash the adzuki beans by hand for 20 minutes or longer each day before boiling them over a low flame. They add salt and soy sauce to raise the sweetness.

Although regular customers who sampled the finished confections in April complained about the “different taste,” Kozuma firmly believes their efforts provide added value in terms of health benefits.

“Even though our confections’ taste scores no more than 80, the healthy factor gives it a 100 rating,” Kozuma said.

Tenmando’s unsweet Japanese-style products fashioned from crystalline fructose have attracted considerable attention, with more male patrons in their 20s to 30s showing up at the shop than before.

In the hope of changing the conventional image of traditional sweets and luring younger consumers, Kozuma and Higashi are touting Tenmando as a “Japanese-style confectionery shop where super health-conscious men turn out.”

Tenmando pitched its limited-time-only “zenzai” adzuki soup for 150 yen ($1.32) on Nov. 10 with a campaign that puns on the date to raise awareness of rare sugars existing in tiny amounts in nature. The date 11/10 can read “ii to” (good sugar) in Japanese.

“Our hope is that more of our customers will enjoy our Japanese sweets that don’t increase blood-sugar levels and lead healthier and happy lives,” Kozuma said.