Primary small bowel bezoars are rare and may cause acute abdomen due to small bowel obstruction (SBO). A 70-year-old Japanese woman presented to the emergency room with abdominal pain, nausea and vomiting. The patient reported that she had eaten a large amount of highly-concentrated, agar dissolved in boiling water two days prior to presentation. Double balloon enteroscopy (DBE) revealed that white-colored, hard bezoars were clogged in the jejunum. At surgery, many bezoars were found impacted in the distal jejunum, and enterotomy was performed. The bezoars were elastic hard, crystallized objects. These bezoars were considered to have formed from highly-concentrated, dissolvable agar.