Question: Who is the only child of the Japanese princess born in 1963?

Context paragraphs:
Princess Takata: Princess Takata (田形皇女 , 674–728) was a Japanese princess during the Asuka period and Nara period of Japanese history.  She was a daughter of Emperor Tenmu and Lady Ōnu whose father was Soga no Akaye.  Prince Hozumi was her older brother, and Princess Ki was her older sister.  She was a "Saiō".

Princess Taki: Princess Taki (託基皇女 , d. February 25, 751) was a Japanese princess during the Asuka period of Japanese history.  She was a daughter of Emperor Tenmu, a wife of Prince Shiki and the mother of Prince Kasuga.  She was a Saiō.

Princess Sakahito: Princess Sakahito (酒人内親王 , Sakahito Naishinnō , 754 – September 25, 829) was a Japanese princess, born a daughter of Emperor Kōnin.

Masako, Crown Princess of Japan: Masako, Crown Princess of Japan (皇太子徳仁親王妃雅子 , Kōtaishi Naruhito Shinnōhi Masako ) , born Masako Owada (小和田雅子 , "Owada Masako" ) on 9 December 1963, is the wife of Naruhito, Crown Prince of Japan, who is the eldest son of Emperor Akihito and Empress Michiko and the heir apparent to the Chrysanthemum Throne.  She is a member of the Imperial House of Japan through marriage.  Should the Crown Prince ascend the throne as expected upon his father's abdication, Masako will become empress consort.

Aiko, Princess Toshi: Aiko, Princess Toshi (敬宮愛子内親王 , Toshi-no-miya Aiko Naishinnō , born 1 December 2001) is the only child of Crown Prince Naruhito and Crown Princess Masako of Japan.

Princess Ki: Princess Ki (紀皇女) was a Japanese princess during the Asuka period of Japanese history.  She was a daughter of Emperor Tenmu and Lady Ōnu, whose father was Soga no Akaye.  Her brother was Prince Hozumi and her sister Princess Takata.

Princess Sumiko: Princess Sumiko (1829-1881), was a Japanese princess.  She was the head of the Katsura-no-miya from 1863 until 1881.

Princess Ōku: Ōku (Japanese 大来皇女 or "大伯皇女") (February 12, 661 – January 29, 702) was a Japanese princess during the Asuka period in Japanese history.  She was the daughter of Emperor Tenmu and sister of Prince Ōtsu.  As a young girl, she witnessed the Jinshin War.  According to the "Man'yōshū" ("The Anthology of Ten Thousand Leaves"), she became the first "Saiō" to serve at Ise Grand Shrine.  After the death of her brother Prince Ōtsu in 686, she returned from Ise to Yamato to enshrine his remains on Mt. Futakami, before a quiet end to her life at age 40.

Margaret, Countess of Pembroke: Margaret of England (20 July 1346 – October/December 1361) was a royal princess born in Windsor, the daughter of King Edward III of England and his consort, Philippa of Hainault.  Margaret would be the last princess born to a reigning English monarch for over a century, until the birth of Elizabeth of York in 1466.  She was also known as Margaret of Windsor.

Princess Ōe: Princess Ōe (大江皇女 , Ōe no himemiko ) (died 699) was a Japanese princess who lived during the Asuka period.  She was a daughter of Emperor Tenji.  Her mother was Lady Shikobuko (色夫古娘), daughter of Oshiumi no Miyakko Otatsu (忍海造小竜).  Ōe's siblings included Prince Kawashima and Princess Izumi.

Supporting paragraphs: Aiko, Princess Toshi Masako, Crown Princess of Japan
Answer: Aiko, Princess Toshi