YOTSUBA&! by Kiyohiko Azuma
From Wikipedia:
Yotsuba&! is the complete opposite of "I Am A Hero"Yotsuba&! is centered on Yotsuba Koiwai, a five-year-old adopted girl who is energetic, cheerful, curious, odd, and quirky — so much so that even her own father calls her strange. She is also initially ignorant about many things a child her age would be expected to know, among them doorbells, escalators, air conditioners, and even playground swings. This naïveté is the premise of humorous stories where she learns about, and frequently misunderstands, everyday things.
At the start of the series, Yotsuba and her adoptive father, Yousuke Koiwai, relocate to a new city with the help of Koiwai's best friend, an impressively tall man nicknamed Jumbo. Yotsuba makes a strong impression on the three daughters of the neighboring Ayase family, Asagi, Fuuka, and Ena. Most of her daily activities and misadventures often originate from interactions with these characters.
The series has no continuing plot—the focus of the stories is Yotsuba's daily voyage of discovery. Many chapters take place on successive days (for details, see List of Yotsuba&! chapters), so that the series follows, almost literally, the characters' daily lives. The tone can be summarized by the motto, used on chapter title pages and advertising, "Today is always the most enjoyable day" (いつでも今日が、いちばん楽しい日 Itsudemo kyō ga, ichiban tanoshii hi), or in the original translation, "Enjoy Everything".
I love this book for it's wonderful line art, as well as the fun and innocent story lines. I usually find myself smiling and laughing when I read these stories of this funny little kid.
I am happy to say, Yotsuba&! is for all ages!!
Yen Press has translated & published all 13 volumes, the last which came out in 2016. I hope there will be more to come one day.
By the way, do you know the meaning of Yotsuba? Yotsuba is a lucky clover (four leaf clover). You might have noticed some similarity in Yotsuba's hair, and a four leaf clover.

This name can be used as 四葉, 四つ葉 or よつ葉 with 四 (shi, yo, yo'.tsu, yo.tsu, yon) meaning "four" and 葉 (you, ha) meaning "blade, fragment, leaf, lobe, needle, piece, plane, spear."
As a word, Yotsuba (四つ葉) refers to a plant having four leaves on one stalk.
Fictional bearers of this name include Yotsuba (四葉) from Sister Princess and Yotsuba Koiwai (小岩井 よつば), the lead character from Yotsuba&! (よつばと! in Japanese).
This name is rarely given to girls, if given at all.

Yotsuba by Michael Foertsch, on Flickr

Yotsuba by Michael Foertsch, on Flickr

Yotsuba by Michael Foertsch, on Flickr
Some random pages....

Yotsuba by Michael Foertsch, on Flickr

Yotsuba by Michael Foertsch, on Flickr

Yotsuba by Michael Foertsch, on Flickr