One of the strongest elements of “Hawaii Five-0” is the theme of family. It is probably the best reason why the show has lasted for 10 seasons. Stories involving family members is certainly no stretch of the imagination for a prime-time series, but the concept of ohana is really what sets the show apart from other formulaic television dramas.

In Hawaiian, ohana literally means, “family, relative, kin group; related,” and it is very unique how the members of Five-0 treat each other’s family members like their own. Wives and husbands are extended members of the team. Children, siblings and cousins are cherished and protected. This certainly helps to create a deeper feeling of ohana within the show. Since the start of the series we have met many family members of the Five-0 team but in the ninth season several made guest appearances that were key to several important plot points for the year.

SIBLING RIVALRY

This season, siblings made things a little difficult for two members of the team — McGarrett’s (Alex O’Loughlin) sister Mary (Taryn Manning) and Lou’s (Chi McBride) brother Percy (Clifton Powell). Mary has always been an entertaining presence in McGarrett’s life, and this season she definitely brought the humor in “Ho‘okahi no la o ka malihini” (“A Stranger Only for a Day”) when she arrives in Hawaii for a visit. Mary figures out a way of spending more time with her big brother Steve by getting him to help her check out her creepy Airbnb neighbor. She suspects correctly that he has a meth lab in his basement. It’s an interesting way for Mary to continue to bond with her brother.

Lou’s conflict with his big brother Percy took a couple of episodes to work out, but in the end, they seem to have buried their differences and are new business partners. Percy was introduced in the Thanksgiving episode, “Lele pu na manu like” (“Birds of a feather”). He is a very good baker, and his talent at baking renews an old sibling rivalry, which ends on a good note. At the end of the season, Lou has invested in Percy and Flippa’s (Shawn Mokuahi Garnett) new business selling Percy’s baked goods.

While not a sibling, Flippa certainly is as close to a brother as Kamekona (Taylor Wily) has in life. This season Flippa had several opportunities to show his own brand of business acumen, as well as his talent as a singer and musician. He definitely showed his ability to recognize and capitalize on raw talent when he tastes it: He sells Percy’s kouign-amann to several local bakeries around the island. But Flippa was at his best when his drummer is murdered in “Ikiiki i ka la o Keawalua” (“Depressed with the heat of Keawalua”). When he mourns his friend’s death and is able to say goodbye at a special memorial by singing Brother Noland’s song “Great Hawaiian Man,” we certainly had a chance to see all sides of Flippa, and more of Garnett’s talent.

WIVES AND DAUGHTERS

Right now, only two members of the team are happily married — Lou and Sgt. Duke Lukela (Dennis Chun). Duke’s wife, Nalani (Laura Mellow), made a quick appearance in “ʻAʻohe kio pohaku nalo i ke alo pali” (“On the slope of the cliff, not one jutting rock is hidden from sight”) when McGarrett visits Duke at his home before his reinstatement hearing. Nalani is often seen supporting Duke and always emits warmth and genuine aloha. Nalani and Duke’s relationship always looks and feels authentic, and that could be because they are real-life partners off-screen as well.

Lou’s wife, Renee (Michelle Hurd), made only one appearance this season in the Thanksgiving episode, but she has been an important part of establishing Lou’s character and his strong sense of family. The episode, coincidentally written by McBride, focused on the Grover family sharing Thanksgiving in Hawaii. Always a voice of reason, Renee never fails at helping Lou make peace with whatever demons he struggles with — which includes accepting his unconventional sibling Percy.

While not a wife, Grace Williams (Teilor Grubbs), as Danny’s daughter (Scott Caan), made a dramatic appearance this year, in an episode that was both emotional and healing for Daddy Danno. In “Ka hauli o ka mea hewa ‘ole, he nalowale koke” (“A bruise inflicted on an innocent person vanishes quickly”), Grace and her friend Katie are critically injured in a car accident, and the team has to investigate what happened in order to clear her name. The episode not only showed how much Danny and his ex-wife, Rachel (Claire van der Boom), love their daughter, but how much Uncle Steve and the rest of the team care for and adore Grace.

FATHERS AND SONS

One of the saddest storylines this year has to be between Junior (Beulah Koale) and his father, Natano Reigns (Eric Scanlan). While they both seem to be mourning the death of Junior’s sister Maya, there also seems to be much more to their story. It may have only been partially revealed this season, yet after Junior helps parole the man who killed Maya, Natano disowns Junior, telling him, “You are not my son.” It was a heartbreaking end to the ninth season, and one storyline that we hope changes for the better come season 10.

Wendie Burbridge writes the “Five-0 Redux” and “Magnum Reloaded” blogs for staradvertiser.com. Follow her on Twitter and Instagram.