John Clayton “Jack” Koser Jr., age 66, of Hudson, Michigan, passed away on Thursday, August 21, 2025, at Hillsdale Hospital surrounded by his loving family.
Born on July 7, 1959, in Toledo, Ohio, Jack was the son of John and Dona (Yarger) Koser Sr. He graduated from Whitmer High School in 1977 and went on to build a long and dedicated career with Modern Builders Supply. As an outside sales representative, he served the company faithfully for 43 years before retiring.
On November 8, 1986, Jack married Rebecca Landin in Toledo. Together they shared over 38 wonderful years of marriage and raised a family of three children.
Outside of work, Jack devoted much of his time to coaching youth sports. Whether it was volleyball, softball, soccer, or hockey, he found great joy in mentoring young athletes—especially his own children. His passion for coaching left a lasting impact on many families throughout the community.
Above all else, Jack cherished his grandchildren and took immense pride in being part of their lives. He also had a special fondness for his truck, which brought him simple joy.
To cherish his memory, Jack leaves his loving wife, Becky; a son, John (Sara) Koser III; two daughters, Jessica (Andrew) Rittenhouse and Rachel (Jacob) Enerson; three siblings, Vicki (Joe) Montgomery, Doug (Michele) Koser, and Mark (Tracy) Koser; six grandchildren: Chelsea, Madelyn, Easton, Lucy, Warren, and Charlotte; and many other beloved family members. He was preceded in death by his parents and a brother, Michael Koser.
The family will receive friends for visitation at the Anderson-Marry Funeral Home, Adrian, on Monday, August 25, 2025, from 2:00 to 7:00 pm.
Friends can express sympathies to the family online by visiting the tribute wall at www.marryfh.com. Memorial contributions in honor of Jack may be made to the ALS Association. Arrangements have been made with the guidance of the Anderson-Marry Funeral Home, Adrian.