We developed a new softening technology applicable to the main body of the jumbo squid Dosidicus gigas; this will aid in squid consumption by elderly individuals and those who have masticatory and dysphagia problems. Protease solutions were injected into jumbo squid and hardness was measured using a texture analyzer. Seven enzymes were tested. Jumbo squid became progressively softer during bromelain and collupulin treatment; the hardness attained 5.6 × 10 3 N/m 2 at bromelain concentrations of 1.00% (w/v) and 6.7 × 10 3 N/m 2 at collupullin concentrations of 1.00% (w/v). The extents of tissue softening after bromelain and collupulin injection to 0.1%, 0.25%, 0.50%, and 1.00% (all w/v) were evaluated; the squid retained its shape after steaming for 10 min at 100°C to inactivate the enzymes. Thus, the results of this research indicate that enzyme injection softens the texture of jumbo squid.