Sorry to bring back this topic, but I want to get something straight here, before people understand something wrong about the game...
Laguna is Squall's father. There is no scene in the whole game where they say Squall's parents died in the war.
Also, Squall was the only one in the orphange that time that called her Sis. Afterwards, yes, Quistis also calls her Sis.. She's just a copycat...
Story:
Laguna ends up at Winhill. A woman has adopted a little girl called Ellone, and he starts to love this little girl. Thanks to her, he ends up being in love with the woman, Raine. They make love, and then Ellone gets kidnapped by Esthar Soldiers. Laguna, being the hero, tries to save Ellone. He manages to save her, but heres about Adel being a corrupted president. In the meantime, Raine is pregnant, waiting for her love to come home... but he doesn't, becuz he needs to save Esthar from this evil sorceress. Laguna sends Ellone back to Winhill, cuz there she will be save. But when Ellone arrives at Winhill, Raine is dead, and she, together with the little baby called Squall, is sent to an orphange. Later on, Matron has continued with her plan of Garden, and brought all the children to Balamb, Trabia and Galbadia Garden, except for Ellone, who is sent back to Laguna, who now is president. Remember, Laguna doesnt know anything about Squall's existent, he doesnt know Raine was pregant!!
How do I know this?
-For one, it has been literally told in the game that Raine was pregnant.
-Squall is the only one that close to Ellone, cuz they are almost bro and sis.
-Laguna and Squall are connected
-Laguna and Squall look much alike, except for Squall having his mothers hair
-Laguna and Raine are married, so they can easily make love, wouldnt you say?
-Kiros says to Squall that he is happy he doesnt look much like his father
Now, doesnt this hint out that Squall is Laguna's son? Also, Raine's last name is probably Leonheart.
And, it has been officially said by Squaresoft too,