Kazuki Morizono (森園 一輝, Morizono Kazuki) is a wealthy businessman who is engaged to Rena Ichinose. He is the son of one of her father's friends, thus appears to be a respectable and mature man. As a result, Rena does not oppose the match, particularly because she does not want to worry her parents after repeatedly pursuing unsavoury men in the past.
However, Rena immediately expresses doubts towards her fiancé, remarking to her friends that his discussions with her are completely superficial. Furthermore, she instinctively dislikes his confident attitude, even though she cannot find any apparent or obvious faults with him. Out of concern for Rena, Teru agrees to join Rena for a luncheon with Morizono at a hotel. The meeting is interrupted when Morizono is called away by Chiharu Mori and Teru is attacked by Akira. The incident unsettles Rena, though no immediate connection is made between the attack on Teru and Morizono's sudden departure.
Shortly after the incident, Morizono appears at Rena's school and insists on taking both Rena and Teru to dinner. Rena is forced to leave early and Morizono reveals that he wants Teru to contact DAISY in regards to the Jack Frost virus. Teru rebuffs Morizono, despite his attempts to upset her into giving information on DAISY. Tasuku Kurosaki later contacts Morizono as DAISY and manages to unsettle Morizono, with Kurosaki deciding that Morizono is not the true threat in the situation with the revived Jack Frost.
After Rena's friends assure her that they will support her decision regarding Morizono, she overhears Morizono discussing the production and sale of a modified version of Jack Frost. When she attempts to break off her engagement with him, Morizono abducts Rena, asserting that his status and her reputation will prevent anyone from believing that she has been kidnapped. He goes forth with their engagement party, where he intends to demostrate and auction off Jack Frost.
Rena manages to deliver a coded message to Teru and her friends, who stage a rescue with the aid of Rena's parents during the engagement party. Through off by the appearance of Teru at the party, Morizono panics after Kurosaki successfully prevents Jack Frost from being distributed and is abandoned by Antler, the person who originally provided him with Jack Frost. His engagement with Rena is broken off afterward.