Nakanishi was assigned to meet Professor Koujiro Rinko and her assistant Mayumi Reynolds at the Ocean Turtle's helipad and escort them to the primary control room. Along the way, Nakanishi answered Rinko's questions about the Ocean Turtle. After escorting Rinko and Mayumi to the control room, Nakanishi took his leave.
Early in the morning on July 6, 2026, Nakanishi met Koujiro Rinko and Yuuki Asuna at a lounge on the eleventh deck while Rinko and Asuna were talking about a ship that Asuna noticed. Rinko invited Nakanishi to have breakfast together with them, and Nakanishi accepted the offer. Over breakfast, Nakanishi explained that the ship they saw was the escort ship DD-127 «Nagato», but stopped talking midway, as he noticed that the ship was suddenly changing course. Nakanishi immediately informed Kikuoka Seijirou about the abrupt change. Having received instructions, Nakanishi excused himself and left the lounge.
Some time after the Ocean Turtle was invaded later that day, Nakanishi entered the sub control room, and reported the current situation on the Ocean Turtle. In response to Seijirou's questions, Nakanishi gave his opinion on how long the barrier walls would last, then gave a casualty report, a status report on the hull's damage, and finally a report on the Nagato's orders.