Courtesy to my sibling @yalbaystaken, who translated the soccer ball Kinako was holding in the Chrono Stone finale. The messages are adorable.
Let's play soccer! - Mark Evans (Endou Mamoru).
Come back again. - Axel Blaze (Gouenji Shuuya).
We'll play soccer again! - Arion Sherwind (Matsukaze Tenma).
I wanted to play more soccer with everyone. - J.P. Lapin (Nishizono Shinsuke).
Take care! - Ryouma Nishiki (Nishiki Ryouma).
I'll never forget you guys! - Skye Blye (Sorano Aoi).
See ya. - Jade Greene (Seto Midori).
I want to see you again! - Rosie Redd (Yamana Akane).
Let's meet again! - Victor Blade (Tsurugi Kyousuke) (yes, with the exclamation mark. he's adorable)
We'll always be friends. - Riccardo Di Rigo (Shindou Takuto).
I really had fun. - Sol Daystar (Amemiya Taiyou).
EDIT: On the rightmost lowest hexagon, it can be guessed that it says:
We'll always we waiting for you - Subaru Honda (Kurumada Goichi). (Only "itsudemo matte" / "always wait" can be seen, alongside with "Kurumad". The rest is an educated guess.)
I'd like to meet you again - Wanli Changcheng (Amagi Daichi). (Only "meet"/"ai" and "want"/"hoshii" can be seen. Half of a kanji is there too, and given its shape and that it's on the same hexagon as Kurumada, we can deduce it's Wanli's name.)
Come back again! - Aitor Cazador (Kariya Masaki).
Come back to play! - Lucien Dark (Kageyama Hikaru) (approximated translation, as not everything was visible).
Do your best, everyone! - Samguk Han (Sangoku Taichi).
Come back any time. - Celia Hills (Otonashi Haruna).
Take care of your health. - Jude Sharp (Kidou Yuuto).
EDIT: On the second image, on the leftmost lowest hexagon, these messages can be inferred:
Let's meet again. - Hugh (Nanasuke Ichino). Between both perspectives, "Mata", "ao yo" (the full message) and "Nanasuke" can be seen.
I had fun. - Shun (Aoyama Shunsuke). "Tanoshi" "ta yo" and the kanji for "Ao" can be seen. The rest is a guess.
Meanwhile, on the other side, there are two cut hexagons:
On the top one, you can make out "mata" and the kanji for "Haya" below - Hayami/Eugene's name. The message is probably something along the lines of "mata ne"/"see you" or some such.
Over it, there's the kana for "chi", and nothing else. If we take into account the other image (upper left), we can see the last kanji for Hamano/Adé's name, so it's his message. There are two lines of kanas above his signature, but we can't make them out well - the second one is "to". Any ideas?
On the lowest rightmost hexagon, there's the kanji for "gen", presumably part of "genki (de)" (translation: "Stay well". It's used when you don't expect to see the person for a long while). There's no kanji to see who it belongs to. The people without a confirmed message are Kurama/Michael and Kirino/Gabi, so pick your poison.
(Fun fact: in the localization, at least the Spanish one, they erased the messages outright. My childhood was a lie.)