August 4 vs Chunichi at Nagoya Dome – Okamoto recorded his twentieth home run of the season and became the fifth player in Giants history to hit twenty home runs in one year during or before the season they turned twenty-two. The other four players: Shigeo Nagashima (1958), Sadaharu Oh (1962), Hideki Matsui (1994-1996), and Hayato Sakamoto (2010).
September 8 vs Hanshin at Koshien Stadium – Okamoto blasted his thirtieth home run of the year (fourth in as many games) and joined Sadaharu Oh, Hideki Matsui, and Hayato Sakamoto as the only players in Giants history to hit thirty home runs during the season they turned twenty-two.
October 9 vs Hanshin at Koshien Stadium – Okamoto went 2-for-5 with two home runs and three RBI. He pushed his home run total to thirty-three and his RBI total to 100. At twenty-two-years and three months, Okamoto became the youngest player in NPB history to bat .300 with thirty home runs and 100 RBI. The previous record of twenty-three years and two months was set by Tetsuto Yamada in 2015. He also became the youngest player in NPB history to record 100 RBI.
Okamoto played in all 143 games this season. He is the first Giant twenty-two or under to play in every game of the season since Hayato Sakamoto in 2008.
Okamoto’s uniform number will change from 38 to 25 for the 2018 season. He will become the thirtieth player in Yomiuri Giants history to wear the number.
Source: Sponichi 11/19/2017
Okamoto wanted to become a pastry chef when he was a child.
Source: Nikkan Sports 12/4/2017
June 2 vs Orix at Kyocera Dome – Okamoto became the eighty-ninth player to bat clean-up for the Yomiuri Giants. At twenty-one years and eleven months, he also became the first Yomiuri player under twenty-two to bat clean-up since Hideki Matsui on August 25, 1995 at twenty-one years and two months. He is the eleventh player in Yomiuri history to hit a home run in their first game as a clean-up hitter and fourth player to hit a home run in their trip to the plate as a clean-up hitter. The other three Yomiuri players that hit home runs in their first plate appearance as a clean-up hitter: Isao Shibata in 1969, Davey Johnson in 1976, and Shinnosuke Abe in 2007.
October 23 – Tatsunori Hara told reporters one of the first things he wanted to do as new manager of the Yomiuri Giants was to get Okamoto to give up smoking.
Source: Sponichi 10/24/2018
Nobuhiko Matsunaka gave Okamoto a bat during his first year after turning pro. Okamoto likes the way the bat feels now and is planning to use a similar model in 2018. The new bat, made by Under Armour, is 900 grams and weighted toward the head. Okamoto used the bat during Miyazaki fall camp in November 2017.
Source: Sponichi 12/17/2017