CHICAGO -- One of the tasks for the Cubs this offseason was to add an impact arm to the starting rotation.?

The North Siders have signed Japanese free-agent Sh¨­ta Imanaga as their newest addition to check that box.

On Thursday, the Cubs officially announced the signing of Imanaga to a multi-year contract agreement. The sides were able to finalize the deal with the left-hander before his 45-day posting window to make the jump to the Majors from the Yokohama DeNA BayStars closed.

• Get to know Sh¨­ta Imanaga

Per a source, the contract guarantees $53 million over four seasons, but the pact gives the pitcher and ballclub multiple paths forward. After the 2025 and ¡®26 seasons, Chicago will have the option to extend the deal to five years ($80 million total). If the deal is not extended in either offseason, Imanaga will have the right to elect free agency.

The club did not disclose the terms of the deal.

The timeline of the agreement happens to fall in line with the Cubs¡¯ upcoming fan fest. With the deal crossing the finish line on Thursday, Imanaga is expected to be introduced in a press conference prior to Friday night¡¯s opening ceremonies at Cubs Convention in Chicago.

As part of the deal, the Cubs will also have to pay a posting fee to Yokohama of just under $10 million.

Imanaga¡¯s free agency was overshadowed this offseason by fellow Japanese star Yoshinobu Yamamoto -- the 25-year-old righty who netted a 12-year, $325 million pact with the Dodgers. Part of the reason is the fact that Imanaga is entering the Majors at 30 years old, though he is widely considered a front-end rotation arm.

Imanaga is set to join a Cubs rotation that features lefty Justin Steele and right-handers Jameson Taillon and Kyle Hendricks. Behind that group is a growing list of younger arms offering depth for the rotation or bullpen, plus a pack of prospects waiting in the wings.

The general consensus is that Imanaga can immediately step in as a No. 2-3 caliber arm. Last year, while pitching for Yokohama in Nippon Professional Baseball, Imanaga spun a 2.80 ERA in 148 innings with a league-leading 174 strikeouts. Yamamoto was close behind with 169 punchouts.

Imanaga was also a standout during Japan¡¯s run to the 2023 World Baseball Classic crown. The left-hander showed off his four-pitch mix with seven strikeouts and no walks in six innings in the tournament. That included working the first two frames in the gold-medal game victory over Team USA.

Imanaga has posted a 3.18 ERA in 1,002 2/3 innings in his eight NPB seasons, including a 2.53 ERA with 306 strikeouts over 291 2/3 innings in the past two tours. He leans heavily on a low-to-mid 90s fastball, while featuring a splitter, slider and curve that have helped him rack up strikeouts with a controlled walk rate.

Last offseason, another 30-year-old starter from Japan -- righty Kodai Senga -- made a strong transition to the Majors. The Mets signed Senga to a five-year, $75 million deal and he fashioned a 2.98 ERA with 202 strikeouts in 166 1/3 innings. Senga was named an All-Star, placed second in voting for the National League Rookie of the Year Award and finished seventh in NL Cy Young voting.

Imanaga¡¯s deal with the Cubs marks the first major addition of the winter for the team, which opened the offseason with the stunning hiring of manager Craig Counsell. Since Counsell arrived, Chicago has been mostly quiet on the transaction front -- save for an attempt to convince superstar Shohei Ohtani to consider the North Side.

Beyond the rotation, the Cubs still have needs in the bullpen, but adding an impact bat remains a high priority. Chicago has taken a patient approach as the market has taken shape in multiple arenas. That includes remaining connected to free-agent center fielder Cody Bellinger, who was the NL¡¯s Comeback Player of the Year for the Cubs in 2023 and would help solve a few needs for '24 and beyond.